The maximum likelihood estimate of θ is 0.8.
The likelihood function for the sample is:
L(θ) = fY(2.3;θ) x fY(1.9;θ) x fY(4.6;θ)
= (2.3 e^(-2.3/theta) / (6 θ theta)) (1.9e^(-1.9/theta) / (6 theta)) (4.6 e^(-4.6/theta) / (6 theta))
Taking the natural logarithm of both sides, we get:
ln(L(θ)) = ln(2.3) - (2.3/θ) - 3ln(θ) - ln(6) + ln(1.9) - (1.9/θ) - 3ln(θ) - ln(6) + ln(4.6) - (4.6/θ) - 3ln(θ) - ln(6) = 3ln(2.3) - (2.3/θ) - 3ln(θ) - ln(6) + 3ln(1.9) - (1.9/θ) - 3ln(θ) - ln(6) + 3ln(4.6) - (4.6/θ) - 3ln(θ) - ln(6)
To find the maximum likelihood estimate of theta, we need to maximize this expression with respect to theta. We can do this by taking the derivative of the expression with respect to theta, setting it to zero, and solving for theta:
d/dθ ln(L(θ)) = (2.3/θ) - (3/θ) + (1.9/θ) - (3/θ) + (4.6/θ) - (3/θ) = 0 Simplifying this expression, we get:
= (2.3/θ) + (1.9/θ) + (4.6/θ)
= (9/theta)
Multiplying both sides by θ, we get:
2.3 + 1.9 + 4.6 = 9θ
Solving for θ , we get:
θ= (2.3 + 1.9 + 4.6) / 9 = 0.8
Therefore, the maximum likelihood estimate of θ is 0.8.
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Use the Richter scale formula R = log (I / I0) to find the magnitude of an earthquake that has the following intensity. (a) 1,000 times that of I0 (b) 100,000 times that of I0
The magnitude of an earthquake that has the following intensity.
(a) 1,000 times that of I0 , R is 3.
(b) 100,000 times that of I0, R is 5.
What is ritcher scale?
The logarithm of the wave amplitude measured by seismographs is used to calculate the earthquake's Richter magnitude; adjustments are made to account for variations in the distances between different seismographs and the earthquake's epi-centre.
a) I = 1000. I₀
R = log(I / I₀)
= log(1000 I₀ / I₀)
= log(1000)
= log 10³
(i.e., log xⁿ = n log x)
= 3 log 10
R = 3
b) I = 100000 I₀
R = log(I / I₀)
= log(100000 I₀ / I₀)
= log(100000)
= log 10⁵
(i.e., log xⁿ = n log x)
= 5 log 10
R = 5
The magnitude of an earthquake that has the following intensity.
(a) 1,000 times that of I0 , R is 3.
(b) 100,000 times that of I0, R is 5.
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Find the volume of the region bounded above by the surface z=4 cos xsin y and below by the rectangle R: OSXS Rosxs osys VE (Simplify your answer. Type an exact answer, using radicals as needed. Type your answer in factored form. Use integers or fractions for any numbers in the expression)
Answer:
2
Step-by-step explanation:
The region bounded above by the surface z=4 cos xsin y and below by the rectangle R:
We can use a double integral to find the volume of the region:
V = ∫∫R 4cos(x)sin(y) dA
where R is the rectangle defined by:
0 ≤ x ≤ π/2
0 ≤ y ≤ π/2
Then we can evaluate the integral as follows:
V = ∫∫R 4cos(x)sin(y) dA
= ∫0^(π/2) ∫0^(π/2) 4cos(x)sin(y) dxdy
= ∫0^(π/2) [4sin(x)](0 to π/2) dy
= ∫0^(π/2) 4sin(π/2) dy
= 4(sin(π/2))(π/2 - 0)
= 4(1)(π/2)
= 2π
Therefore, the volume of the region bounded above by the surface z=4 cos xsin y and below by the rectangle R is 2π.
Marco is driving to the Grand Canyon. His distance from the Grand Canyon decreases 150 mi every 3 h. After 4 h, his distance from the Grand Canyon is 200 mi. Marco's distance from the Grand Canyon in miles, y, is a function of the number of hours he drives, z. The rate of change is -50, what is the initial value? I NEED HELP ASAP.
Answer: 400 miles
Step-by-step explanation: every hour, his distance decreases by 50 miles. After 4 hours, his distance is 200 miles, so 50 miles times 4 hours = 200 miles+the original 200 miles =400 miles.
2) Find the surface area of the cube.
The calculated value of the surface area of the cube is 294 mm^2
Finding the surface area of the cube.From the question, we have the following parameters that can be used in our computation:
The cube
The side length of the cube is
Length = 7 mm
The surface area of the cube is calculated as
Surface area = 6 * Length^2
Substitute the known values in the above equation, so, we have the following representation
Surface area = 6 * 7^2
Evaluate
Surface area = 294 mm^2
Hence the surface area is 294 mm^2
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The following data was collected from a simple random sample of a population. 13 17 18 21 23 The point estimate of the population mean O a. cannot be determined, since the population size is unknown. Ob. is 18. Oc. is 92. O d. is 18.4.
The point estimate of the population mean is 18.4. Therefore, the correct answer is (d) is 18.4
When conducting a statistical study, it is important to have a good understanding of the population in question. In such cases, a sample of the population can be taken to infer information about the population.
One of the key parameters that is of interest is the population mean. The population mean represents the average value of a particular characteristic in the entire population. However, since it is usually not possible to collect data from the entire population, we use the sample mean as an estimate of the population mean.
In the given scenario, a simple random sample of a population was taken, and the following data was collected: 13, 17, 18, 21, 23. The point estimate of the population mean can be calculated by taking the mean of the sample.
The sample mean is calculated as follows:
(13 + 17 + 18 + 21 + 23) / 5 = 92 / 5 = 18.4
Therefore, the point estimate of the population mean is 18.4, option (d).
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Find the volume of the region in the first octant bounded by the coordinate planes, the plane y + z = 2 , and the cylinder x = 4 − y 2 .
To find the volume of the region in the first octant bounded by the coordinate planes, the plane y + z = 2, and the cylinder x = 4 − y^2, we need to first graph the given surfaces in 3D space.
The coordinate planes are the x-y, x-z, and y-z planes. In the first octant, these planes bound the region from below and on the sides.
The plane y + z = 2 is a plane that passes through the origin and intersects the y-z plane at y = 2 and z = 0, and the z-x plane at x = 2 and z = 0,The cylinder x = 4 − y^2 is a cylinder with radius 2 and centered at the origin, since it is a function of y^2 and only extends to y = 2 in the first octant.
To find the volume of the region bounded by these surfaces, we need to integrate over the region. We can do this by dividing the region into small rectangular prisms, and integrating over each prism.The limits of integration for x are 0 to 4 − y^2, the limits for y are 0 to 2, and the limits for z are 0 to 2 − y.
Therefore, the volume of the region is given by the triple integral: ∫∫∫ (dV) = ∫0^2 ∫0^(4-y^2) ∫0^(2-y) dz dxdy.
Evaluating the integral, we get: ∫∫∫ (dV) = ∫0^2 ∫0^(4-y^2) (2-y) dx dy
∫∫∫ (dV) = ∫0^2 (2-y)(4-y^2) dy
∫∫∫ (dV) = ∫0^2 8-4y^2-2y+ y^3 dy
∫∫∫ (dV) = [8y - 4y^3/3 - y^2 + y^4/4]0^2
∫∫∫ (dV) = 32/3, Therefore, the volume of the region in the first octant bounded by the coordinate planes, the plane y + z = 2, and the cylinder x = 4 − y^2 is 32/3 cubic units.
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solve 4 sin ( 2 x ) = 2 for the two smallest positive solutions a and b, with a < bA =B =Give your answers accurate to at least two decimal places.
The two smallest positive solutions for 4 sin(2x) = 2 are x = π/12 and x = 5π/12.
How to solve the equation?Starting with 4 sin (2x) = 2, we can simplify it by dividing both sides by 4 to get:
sin (2x) = 1/2
To solve for the two smallest positive solutions a and b, we need to find the values of 2x that satisfy sin (2x) = 1/2.
We know that sin (π/6) = 1/2, so one solution is 2x = π/6, which means x = π/12.
The next solution can be found by adding the period of sin (2x), which is π. Therefore, the next solution is 2x = π - π/6 = 5π/6, which means x = 5π/12.
Thus, the two smallest positive solutions for x are:
a = π/12 ≈ 0.26
b = 5π/12 ≈ 1.31
Therefore, the solution is a = 0.26 and b = 1.31.
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Automobiles arrive at the drive-through window at the downtown Baton Rouge, Louisiana, post office at the rate of 4 every 10 minutes. The average service time is 2 minutes. The Poisson distribution is appropriate for the arrival rate and service times are negative exponentially distributed.
a. What is the average time a car is in the system?
b. What is the average number of cars in the system?
c. What is the average number of cars waiting to receive service?
a. Using poisson distribution The average time a car is in the system, considering waiting in line and receiving service, is 12 minutes.
b. The average number of cars in the system, considering both waiting in line and receiving service, is 10.8 cars.
c. The average number of cars waiting to receive service is 10 cars.
a. The average time a car is in the system can be calculated as the sum of the average time spent waiting in line and the average time spent receiving service. Let's calculate each of these separately:
Average time spent waiting in line: Since arrivals follow a Poisson distribution with a rate of 4 every 10 minutes, the interarrival time (time between consecutive arrivals) follows an exponential distribution with parameter λ = 4/10 = 0.4.
The average interarrival time is 1/λ = 2.5 minutes. By Little's law, the average number of cars waiting in line is equal to the product of the arrival rate and the average time spent waiting, which is 4(2.5) = 10 minutes.
Average time spent receiving service: Since service times are exponentially distributed with a mean of 2 minutes, the average time spent receiving service is also 2 minutes.
Therefore, the average time a car is in the system is 10 + 2 = 12 minutes.
b. The average number of cars in the system can be calculated as the sum of the average number of cars waiting in line and the average number of cars receiving service. Since service times are exponentially distributed and arrivals follow a Poisson distribution, the system can be modeled as an M/M/1 queue.
The average number of cars waiting in line can be calculated using Little's law, which gives us 4(2.5) = 10 cars. The average number of cars receiving service can be calculated as the ratio of the average service time to the average interarrival time, which is 2/2.5 = 0.8 cars. Therefore, the average number of cars in the system is 10 + 0.8 = 10.8 cars.
c. The average number of cars waiting to receive service can be calculated as the difference between the average number of cars in the system and the average number of cars receiving service. Therefore, the average number of cars waiting to receive service is 10.8 - 0.8 = 10 cars.
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Consider the circular paraboloid z = x^2 + y^2 and the line through the point (2,0,0) and with direction vector (-1, a, 1). Find all values for a where the line will intersect the paraboloid in only a single point.
The line through the point (2,0,0) and with direction vector (-1, a, 1) intersects the paraboloid z = x² + y² in only a single point for a = 0 or a = √(2).
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To find the intersection points, we can substitute the equation of the line into the equation of the paraboloid:
z = x² + y²
z = (2-t)² + a*t²
x = 2-t
y = a*t
where t is the parameter for the line.
Substituting x and y into the equation of the paraboloid gives:
z = (2-t)² + a^2*t²
To find the values of a where the line intersects the paraboloid in only a single point, we need to find the values of a where this equation has exactly one solution. This occurs when the discriminant of the quadratic equation in t is zero:
a²*(2-a²) = 0
a = 0 or a = √(2)
Therefore, the line through the point (2,0,0) and with direction vector (-1, a, 1) intersects the paraboloid z = x² + y² in only a single point for a = 0 or a = √(2).
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Complete the square and find the indefinite integral. (Remember to use absolute values where appropriate. Use C for the constant of integration.) ∫ x / √(x^2-6x+39) dx
The indefinite integral is ∫ x / √(x^2 - 6x + 39) dx = √(x^2 - 6x + 39)/2 + C.
To complete the square in the denominator of the integrand, we need to add and subtract a constant:
x^2 - 6x + 39 = (x^2 - 6x + 9) + 30 = (x - 3)^2 + 30
So we can rewrite the integrand as:
x / √[(x - 3)^2 + 30]
Next, we can use the substitution u = (x - 3)^2 + 30 to simplify the integral. Then, du/dx = 2(x - 3), which means dx = du/(2(x - 3)). Making this substitution gives:
∫ x / √[(x - 3)^2 + 30] dx = 1/2 ∫ du/√u
Now, we can use the substitution v = √u, which means dv/dx = 1/(2√u) du/dx = 1/(2√u)(2(x - 3)) = (x - 3)/√u, and dx = 2v dv/(x - 3). Making this substitution gives:
1/2 ∫ du/√u = 1/2 ∫ dv = 1/2 v + C
Substituting back for v and u, we get:
1/2 ∫ x / √[(x - 3)^2 + 30] dx = 1/2 ∫ dv = 1/2 √[(x - 3)^2 + 30] + C
Therefore, the indefinite integral of x / √(x^2 - 6x + 39) dx is:
∫ x / √(x^2 - 6x + 39) dx = √(x^2 - 6x + 39)/2 + C
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For f(x) = 2x³ 3x² - 36x 5 use the second derivative test to determine local maximum of f.
The second derivative test of the function is solved and the local maximum point of the function is at x = -1/2
Given data ,
Let the function be represented as A
Now , the value of A is
f ( x ) = 2x³ + 3x² - 36x + 5
Now , the first derivative of f(x) to obtain f'(x) is
f'(x) = 6x² + 6x - 36
And , the second derivative of f(x) by differentiating f'(x) with respect to x is
f''(x) = 12x + 6
Now , Set f''(x) = 0 and solve for x to find the critical points.
12x + 6 = 0
12x = -6
x = -6/12
x = -1/2
For x < -1/2: Since f''(x) = 12x + 6, and x < -1/2, the value of f''(x) will be negative, indicating that the function is concave down in this interval, and there is no local maximum point.
For x > -1/2: Since f''(x) = 12x + 6, and x > -1/2, the value of f''(x) will be positive, indicating that the function is concave up in this interval, and there may be a local maximum point.
And , If f'(x) is continuous at x = -1/2, then there must be a local maximum point at x = -1/2 since f''(x) changes sign at x = -1/2. We may verify the value of f'(x) at x = -1/2 to see if f'(x) is continuous at x = -1/2.
f'(-1/2) = 6(-1/2)² + 6(-1/2) - 36 = 3 - 3 - 36 = -36
Since f'(-1/2) = -36 is a finite function, we may infer that f'(x) is continuous at x = -1/2 and that x = -1/2 is the location of the local maximum
Hence , the local maximum is at x = -1/2
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write an equation for a line that is perpendicular to the line y-4=2/3(x-9) that goes through the point (6,-5)
Answer:
y = (-3/2)x + 4.
Step-by-step explanation:
y - 4 = (2/3)(x - 9)
y = (2/3)x - (2/3)(9) + 4
y = (2/3)x - 2
The slope of this line is 2/3.
A line that is perpendicular to this line will have a slope that is the negative reciprocal of 2/3. To find the negative reciprocal, we flip the fraction and change the sign:
slope of perpendicular line = -3/2
Now we can use the point-slope form of the equation of a line, which is:
y - y1 = m(x - x1)
where m is the slope of the line, and (x1, y1) is a point on the line.
Substituting the given point (6,-5) and the slope -3/2, we get:
y - (-5) = (-3/2)(x - 6)
y + 5 = (-3/2)x + 9
y = (-3/2)x + 4
Therefore, the equation of the line that is perpendicular to y - 4 = (2/3)(x - 9) and passes through the point (6,-5) is y = (-3/2)x + 4.
There is in M prime number 2,3,5,7and in N odd number 1,3,5,7,9 what is type of relation between set m and n
The type of relationship between the sets M and N is intersection.
What is a set?A set is a collection of well ordered items.
Given that there is in M prime number 2,3,5,7 and in N odd number 1,3,5,7,9 what is type of relation between set m and n?
We note that set M contains 4 elements. Also, set N contains 5 elements.Now, set M and set N have 3 elements in common. These are 3, 5 and 7. Since both sets have these 3 elements in common, there is an intersection of the two sets.So, the type of relationship between the sets M and N is intersection.
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given a two-tailed test, using a sample of 10 observations and alpha equal to 0.10, the critical value is ± 1.697.
A two-tailed test is used in sample of 10 observations with an alpha level of 0.10. The critical value for this test is ± 1.697. These critical values are used to determine the rejection region of your hypothesis test.
In a two-tailed test with a sample of 10 observations and alpha equal to 0.10, the critical value would be ±1.697. This means that if the test statistic falls outside of this range, it would be considered statistically significant and we would reject the null hypothesis. The use of a two-tailed test means that we are interested in testing for the possibility of a difference in either direction, as opposed to a one-tailed test where we would only be interested in a difference in one specific direction.
Among the significance tests, single-ended and two-tailed tests are other ways of calculating the significance of the measurements determined from the data set under the test. A two-tailed test is appropriate if the predicted value is greater or less than the value on a test, i.e. whether the test taker will score some points higher or lower. This method is used to test the null hypothesis, if the predicted value is in the critical region, it accepts the alternative hypothesis instead of the null hypothesis. A one-tailed test is appropriate if the estimated value differs from the reference value in one direction (left or right) but not in two directions.
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if a random variable x has the gamma distribution with α=2 and β=1, find p(1.6
To find the probability p(1.6) for a random variable x with a gamma distribution where α=2 and β=1, you'll need to use the gamma probability density function. The gamma is given by:
f(x) = (β^α * x^(α-1) * e^(-βx)) / Γ(α)
where Γ(α) is the gamma function of α.
Now, plug in the values for α, β, and x:
f(1.6) = (1^2 * 1.6^(2-1) * e^(-1*1.6)) / Γ(2)
To calculate Γ(2), note that Γ(n) = (n-1)! for positive integers. In this case, Γ(2) = (2-1)! = 1! = 1.
f(1.6) = (1 * 1.6^1 * e^(-1.6)) / 1 = 1.6 * e^(-1.6)
Therefore, the probability density function value at x=1.6 for a random variable x with a gamma distribution where α=2 and β=1 is:
f(1.6) = 1.6 * e^(-1.6) ≈ 0.33013
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A mass weighing 4 lb stretches a spring 3 in. Suppose that the mass is given an additional 3 in displacement in the positive direction and then released. The mass is in a medium that exerts a viscous resistance of 6 lb when the mass has a velocity of 3 ft/s. Under the assumptions discussed in this section, formulate the initial value problem that governs the motion of the mass.
x(0) = 0.25 in (initial displacement from equilibrium). x'(0) = 0 ft/s (initial velocity)
How to formulate the initial value problem that governs the motion of the mass.We can use Newton's second law to formulate the initial value problem that governs the motion of the mass. The equation is given by:
m*a = F_net
where m is the mass, a is the acceleration, and F_net is the net force acting on the mass.
The net force can be found as the sum of the spring force, the viscous resistance force, and the force due to gravity. Therefore, we have:
F_net = F_spring + F_viscous + F_gravity
where F_spring is the force exerted by the spring, F_viscous is the force due to the viscous resistance, and F_gravity is the force due to gravity.
The force exerted by the spring is given by Hooke's law:
F_spring = -k*x
where k is the spring constant and x is the displacement from the equilibrium position. Since the spring stretches 3 in under a weight of 4 lb, we can find k as:
k = F/x = 4/3 = 4/0.25 = 16 lb/in
Therefore, the force exerted by the spring is:
F_spring = -16*x
The force due to viscous resistance is proportional to the velocity of the mass and is given by:
F_viscous = -c*v
where c is the viscous damping coefficient and v is the velocity of the mass. Since the viscous resistance force is 6 lb when the velocity is 3 ft/s, we can find c as:
c = F_viscous/v = 6/3 = 2 lb·s/ft
Therefore, the force due to viscous resistance is:
F_viscous = -2*v
The force due to gravity is given by:
F_gravity = -m*g
where g is the acceleration due to gravity (32.2 ft/s^2).
Substituting these equations into the equation for net force, we get:
ma = -16x - 2v - mg
Since the displacement x and the velocity v are both functions of time t, we can rewrite this equation as a second-order ordinary differential equation in terms of x:
mx'' + 2cx' + kx = m*g
where x' and x'' denote the first and second derivatives of x with respect to t, respectively.
This is the initial value problem that governs the motion of the mass, subject to the initial conditions:
x(0) = 0.25 in (initial displacement from equilibrium)
x'(0) = 0 ft/s (initial velocity)
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Which transformation preserves both distance and angle measure?
A. (x,y) → (2x - 4,y-6)
B. (x,y) → (2x - 4,2y-6)
C. (x,y) → (-2y + 4,x-6)
D. (x,y) → (-y + 4,x-6)
Answer: B. (x,y) → (2x - 4,2y-6)
Step-by-step explanation:
A transformation that preserves both distance and angle measure is called an isometry. An isometry preserves distance because the distance between any two points in the pre-image is the same as the distance between their corresponding points in the image. An isometry also preserves angle measure because the angle between any two intersecting lines in the pre-image is the same as the angle between their corresponding lines in the image.
Option (B) represents a transformation that preserves both distance and angle measure. This transformation is a combination of a horizontal and a vertical stretch (or compression) with a scale factor of 2 and a translation of 4 units to the right and 6 units down. Since a stretch (or compression) preserves angle measure, and a translation preserves distance and angle measure, this transformation preserves both distance and angle measure, and therefore, is an isometry.
Option (A) represents a horizontal stretch with a scale factor of 2 and a translation of 4 units to the left and 6 units down. This transformation does not preserve distance, since the horizontal distances are multiplied by a factor of 2, and it does not preserve angle measure, since the angles between intersecting lines are not necessarily preserved.
Option (C) represents a 90-degree rotation followed by a reflection across the x-axis, which preserves angle measure, but does not preserve distance, since the distances between corresponding points are not necessarily the same.
Option (D) represents a 90-degree counterclockwise rotation followed by a reflection across the y-axis, which preserves angle measure, but does not preserve distance, since the distances between corresponding points are not necessarily the same.
Therefore, the correct answer is option (B).
7/10+2/5=
answer pls
The sum of 7/10 and 2/5 is 29/50.
Answer: 11/10 is the correct answer to this question.
Step-by-step explanation:
First, we take 7/10 and 2/5. The L.C.M of denominators is equal to 10. As the denominator in 7/10 is already 10 we don't change it but as the denominator in 2/5 is 5 we multiply the numerator and denominator with 2 in order to equalize both. Hence we get 7/10 and 4/10. On adding both the numerators we get 11/10.
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PLEASE HELP SOLVE THIS PROBLEM!!?
Answer:
Yes, these two figures are similar because the ratios of corresponding sides are equal.
UR = ST = 2, RS = TU = 3
YV = WX = 4, VW = XY = 6
UR/RS = YV/VW
ST/TU = WX/XY
A virus is spreading across an animal shelter. The percentage of animals infected after t days is given by V(t) = 100/1 + 99 e^-0.186t. A) What percentage of animals will be infected after 11 days? ROUND YOUR ANSWER TO 2 DECIMAL PLACES. (i.e. 12.34%) About % of the animals will be infected after 11 days. B) How long will it take until exactly 90% of the animals are infected? ROUND YOUR ANSWER TO 2 DECIMAL PLACES 90% of the animals will be infected after about days.
a. After 11 days, approximately 91.91% of the animals will be affected.
b. It will take around 20.83 days for 90% of the animals to become infected. The answer, rounded to two decimal places, is 20.83 days.
What is logarithm?A logarithm is defined as the number of powers to which a number must be increased in order to obtain some other numbers. It is the simplest way to express enormous numbers. A logarithm has several key features that demonstrate that logarithm multiplication and division can also be represented in the form of logarithm addition and subtraction.
A) To find the percentage of animals infected after 11 days, we simply substitute t = 11 into the given equation for V(t):
V(11) = 100/ [tex](1 + 99e^{(-0.186*11)})[/tex]
Using a calculator, we get:
V(11) ≈ 91.91%
Therefore, about 91.91% of the animals will be infected after 11 days.
B) To find the time it takes until exactly 90% of the animals are infected, we need to solve the equation V(t) = 90 for t.
Substituting V(t) into the equation, we get:
90 = 100/ [tex](1 + 99e^{(-0.186t)})[/tex]
Multiplying both sides by [tex](1 + 99e^{(-0.186t)})[/tex], we get:
[tex]90 + 90e^{(-0.186t)} = 100[/tex]
Simplifying, we get:
[tex]e^{(-0.186t)} = 1/9[/tex]
Taking the natural logarithm of both sides, we get:
-0.186t = ln(1/9)
Solving for t, we get:
t ≈ 20.83 days
Therefore, about 20.83 days will elapse until exactly 90% of the animals are infected. Rounded to 2 decimal places, the answer is 20.83 days.
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The following data were collected from a case-control study of breast cancer and smoking: case control Smoker 25 15 Non- smoker 75 85 100 100 Statistical inferences for odds ratios are based on the natural log of the odds ratio, rather than the odds ratio itself (because the distribution for an odds ratio does not follow a normal distribution). The sampling distribution of the natural log of the odds ratio (InO
The sampling distribution of the natural log of the odds ratio (lnOR) will be used for further statistical analyses to determine the relationship between smoking and breast cancer therefore lnOR =0.86.
Based on the data provided from the case-control study of breast cancer and smoking, we can calculate the odds ratio (OR) to understand the association between smoking and breast cancer. Here's the data:
- Smoker: 25 cases, 15 controls
- Non-smoker: 75 cases, 85 controls
The odds ratio is calculated as (odds of exposure among cases) / (odds of exposure among controls), which is:
OR = (25/75) / (15/85) = 2.36
However, statistical inferences for odds ratios are based on the natural log of the odds ratio (lnOR) because the distribution for an odds ratio does not follow a normal distribution. To get the lnOR, we take the natural logarithm of the OR:
lnOR = ln(2.36) ≈ 0.86
The sampling distribution of the natural log of the odds ratio (lnOR) will be used for further statistical analyses to determine the relationship between smoking and breast cancer.
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5. Herman is half as old as his teenage sister.
In seven years he will be two-thirds his sister's
age. How old is Herman currently?
Answer:
7
Step-by-step explanation:
Sum of the series (x-y)^2+x^2+y^2
The sum of the series (x-y)^2 + x^2 + y^2 is 2x^2 - 2xy + 2y^2.
Evaluating the sum of the seriesFrom the question, we have the following parameters that can be used in our computation:
(x-y)^2+x^2+y^2
The expression (x-y)^2 can be expanded as:
(x-y)^2 = x^2 - 2xy + y^2
Adding x^2 and y^2, we get:
(x-y)^2 + x^2 + y^2 = x^2 - 2xy + y^2 + x^2 + y^2
Combining like terms, we can simplify this expression to:
(x-y)^2 + x^2 + y^2 = 2x^2 - 2xy + 2y^2
Therefore, the sum of the series (x-y)^2 + x^2 + y^2 is 2x^2 - 2xy + 2y^2.
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how do i write the inequality of this?
Answer:
[tex]y \geqslant \frac{2}{3} x - 2[/tex]
[tex]y + 2 \geqslant \frac{2}{3} x[/tex]
[tex] \frac{2}{3}x - y \leqslant 2[/tex]
[tex]2x - 3y \leqslant 6[/tex]
A tank contains 200 gallons of water in which 300 grams of salt is dissolved. A brine solution containing 0.4 kilograms of salt per gallon of water is pumped into the tank at the rate of 5 per minute, and the well-stirred mixture is pumped out at the same rate. Let A (t) represent the amount of salt in the tank at time t. a) Find the number A(t) of kilograms of salt in the tank at time t. b) How much salt will there be in the tank after a long period of time?
The time period is given by
[tex]A(t) = -40e^{-5t-8.008}+80000[/tex]
How to find the period of time?a) Let's use the following variables:
t: time in minutes
A(t): amount of salt in the tank at time t in grams
V(t): volume of water in the tank at time t in gallons
Initially, the tank contains 300 grams of salt in 200 gallons of water, so the concentration of salt is:
[tex]C(0) = \frac{300g}{200gal} = 1.5g/gal[/tex]
As the brine solution is pumped into the tank at a rate of 5 gallons per minute and at a concentration of 0.4 kilograms of salt per gallon of water, the concentration of salt in the incoming solution is:
[tex]c_{in} = 0.4 kg/gal \times \frac{1000g}{1kg} \times \frac{1gal}{1L} = 400g/gal[/tex]
Let's assume that the tank is well-stirred, so the concentration of salt in the tank is uniform at any given time. Then, we can use the following differential equation to model the amount of salt in the tank:
[tex]\frac{dA}{dt} =c_(in) \times \frac{dV}{dt} - c(t) \times \frac{dV}{dt}[/tex]
where [tex]\frac{dV}{dt}\\[/tex] is the rate of change of the volume of water in the tank. We know that water is pumped into and out of the tank at the same rate of 5 gallons per minute, so [tex]\frac{dV}{dt} = 0[/tex], and the differential equation simplifies to:
[tex]\frac{dA}{dt} = c_(in) \times 5 -c(t) \times 5 = 2000 - 5c(t)[/tex]
This is a separable differential equation that we can solve by separating the variables and integrating:
[tex]\frac{dA}{2000-5c} = dt\\\\ \int \frac{dA}{2000-5c} = \int dt\\\\-\frac{1}{5} ln|2000 - 5c| = t+C\\\\c(t) = -\frac{1}{5} e^(-5t-5C) +400[/tex]
We can find the constant C by using the initial condition c(0) = 1.5, we get
[tex]C = ln3001.5 =8.008\\[/tex]
Therefore, the amount of salt in the tank at time t is,
[tex]A(t) = V(t) \times c(t)\\A(t) = 200 \times (-\frac{1}{5} e^{-5t-8.008}+400 )\\A(t) = -40e^{-5t-8.008}+80000[/tex]
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Five years ago a family purchased a new car that cost 16,490 . If the car lost 13% of its value each year , what is the value of the car now
The value of the car now is approximately $8,920.09.
To solve this problemThe value of the car can now be determined using the compound interest formula:
A = P * (1 - r)^n
Where
A is the total sum P is the sum at the beginning r is the annual interest rate in decimal form n is the number of yearsThe beginning sum is $16,490 in this instance, the yearly interest rate is 13%, or 0.13 as a decimal, and the number of years is 5.
We thus have:
A = 16490 * (1 - 0.13)^5 = 16490 * 0.541 = $8920.09
Therefore, the value of the car now is approximately $8,920.09.
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Cuántas claves de acceso a una computadora será posible diseñar con los números 1,1,1,2,3,3,3,3
The number of unique access keys that can be designed with the given numbers is 280 possible unique access keys.
How to find the number of access keys ?This is a permutations problem which means it can be solved by the equation :
Number of permutations = n! / (n1! * n2! * ... * nk!)
Given the numbers, 1, 1, 1, 2, 3, 3, 3, 3, we can apply the formula to be :
Number of permutations = 8 ! / (3 ! x 1 ! x 4 !)
= 40, 320 / (6 x 1 x 24)
= 40, 320 / 144
= 280 possible access keys
In conclusion, a total of 280 possible unique access keys can be made.
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Use polar coordinates to calculate the area of the region. R = {(x, y) | x2 + y2 ≤ 25, x ≥ 4}
The area of the region R = {(x, y) | x² + y² ≤ 25, x ≥ 4} using polar coordinates is 7π square units.
To calculate the area, first, we need to convert the given equations into polar coordinates. The equation x² + y² ≤ 25 becomes r² ≤ 25, which simplifies to 0 ≤ r ≤ 5. The equation x ≥ 4 can be written as r*cos(θ) ≥ 4. Solving for θ, we get 0 ≤ θ ≤ 2π/3 and 4π/3 ≤ θ ≤ 2π.
Now, use the polar area formula: A = 0.5 * ∫(r² dθ). Integrate r²/2 from 0 to 2π/3 and from 4π/3 to 2π, then multiply by the limits' difference. Finally, add the two areas to find the total area of the region, which is 7π square units.
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Can someone help me with this math problem?
Answer:
Add a dot (Point A) 5 units to the left of point C, a dot (Point B) 7 units below point C, and a final dot (Point D) that is 5 units across from Point B
Step-by-step explanation:
Using the definition of a rectangle (4 right angles)
- Length is usually viewed as left to right
- Width is usually viewed as top to bottom
Diagonals AC and BD intersect at E. ABCD is a rectangle with AC = 10cm and BC =8cm .D2 = 20 degrees. Calculate A1, A2, B1 ,C1, C2,D1, AD, AE and AB
Answer:
A1 = 160 degrees
A2 = 20 degrees
B1 = 70 degrees
C1 = 110 degrees
C2 = 70 degrees
D1 = 20 degrees
AD = 10 cm
AE = 5√5 cm
AB = 8 cm
Step-by-step explanation:
To solve this problem, we can start by using the fact that the diagonals of a rectangle are equal in length and bisect each other. Therefore, we know that:
- BD = AC = 10cm
- AE = EC = BD/2 = 5cm
- AB = CD = sqrt(AC^2 + BC^2) = sqrt(10^2 + 8^2) = sqrt(164) ≈ 12.81cm
- AD = BC = 8cm
To find the angles A1, A2, B1, C1, C2, and D1, we can use the following relationships:
- A1 = 180 - D2 = 180 - 20 = 160 degrees
- A2 = 180 - A1 = 180 - 160 = 20 degrees
- B1 = C2 = D2 = 20 degrees
- C1 = 180 - B1 = 180 - 20 = 160 degrees
- D1 = 180 - C2 = 180 - 20 = 160 degrees
Therefore:
- A1 = 160 degrees
- A2 = 20 degrees
- B1 = C2 = D2 = 20 degrees
- C1 = D1 = 160 degrees
Note that angles A1, C1, and D1 are all equal, as are angles A2, B1, and C2, because opposite angles in a rectangle are equal.
Finally, to find AD, we can use the Pythagorean theorem:
- AD = BC = 8cm
And to find AE, we can use the fact that diagonals bisect each other:
- AE = EC = BD/2 = 5cm
Therefore:
- AD = 8cm
- AE = 5cm
- AB ≈ 12.81cm
- A1 = 160 degrees
- A2 = 20 degrees
- B1 = C2 = D2 = 20 degrees
- C1 = D1 = 160 degrees