A surveying instrument makes an error of -2, -1, 0, 1, or 2 feet with equal probabilities when measuring the height of a 200-foot tower.

(a) Find the expected value and the variance for the height obtained using this instrument once.
(b) Estimate the probability that in 18 independent measurements of this tower, the average of the measurements is between 199 and 201, inclusive.

Answers

Answer 1

(a) The expected value of the height obtained using the instrument once is 200 feet and the variance is 400 square feet.

Let X be the height obtained using the instrument once.

Then X can take on the values of 198, 199, 200, 201, or 202 with equal probabilities of 1/5 each.

The expected value of X is given by:

E(X) = ΣxP(X=x) = (198)(1/5) + (199)(1/5) + (200)(1/5) + (201)(1/5) + (202)(1/5) = 200

The variance of X is given by:

Var(X) = E(X^2) - [E(X)]^2

To find E(X^2), we have:

E(X^2) = Σx^2P(X=x) = (198^2)(1/5) + (199^2)(1/5) + (200^2)(1/5) + (201^2)(1/5) + (202^2)(1/5) = 40000/5 = 8000

Thus, the variance of X is:

Var(X) = 8000 - (200)^2 = 400

Therefore, the expected value of the height obtained using the instrument once is 200 feet and the variance is 400 square feet.

(b) The estimated probability that in 18 independent measurements of the tower, the average of the measurements is between 199 and 201, inclusive, is approximately 0.8664.

Let X1, X2, ..., X18 be the heights obtained in 18 independent measurements of the tower. Then, the sample mean of these measurements, denoted by X-bar, is given by:

X-bar = (X1 + X2 + ... + X18)/18

The expected value of X-bar is the same as the expected value of a single measurement, which is 200 feet. The variance of X-bar is given by:

Var(X-bar) = Var(X1 + X2 + ... + X18)/18^2

Since the measurements are independent, we have:

Var(X1 + X2 + ... + X18) = Var(X1) + Var(X2) + ... + Var(X18)

= 18(400) = 7200

Therefore, the variance of X-bar is:

Var(X-bar) = 7200/18^2 = 20/9

To estimate the probability that X-bar is between 199 and 201, we standardize X-bar by subtracting its mean and dividing by its standard deviation:

Z = (X-bar - 200)/(2/3) = 3(X-bar - 200)/2

Then, we have:

P(199 ≤ X-bar ≤ 201) = P(-1.5 ≤ Z ≤ 1.5) ≈ 0.8664

Therefore, the estimated probability that in 18 independent measurements of the tower, the average of the measurements is between 199 and 201, inclusive, is approximately 0.8664.

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Related Questions

1/10 ÷ 8

Could someone help me with this

Answers

1/80 is the answer for your question

In the coordinate plane, the point A(-2,4) is translated to the point A’(-4,3). Under the same translation, the points B(-4,8) and C(-6,2) are translated to B’ and C’, respectively. What are the coordinates of B’ and C’?

Answers

Answer:

B' (-6, 7)

C' ( -8, 1)

Step-by-step explanation:

The rule is

(x,y) → (x -2, y - 1)

A( -2,4) → A' ( -4,3)

To get from A to A', the x value changed by -2 (-2-2 = -4). The y changed by -1 ( 3-1 = 3)

Helping in the name of Jesus.

Find the absolute maximum and absolute minimum values of f on the given interval. f(t) = 7t + 7 cot(t/2), [pi/4, 7pi/4] absolute minimum value absolute maximum value

Answers

The absolute minimum value of given trigonometric-function is 331.9 and absolute maximum value of the same function is 4403.

What is absolute value?

The non-negative value of x or its distance from zero on the number line, regardless of its sign, is the absolute value, modulus, or magnitude denoted by | x | for any real number x. When a function reaches its absolute minimum value, it has reached its lowest conceivable value, and when it reaches its absolute maximum value, it has reached its highest possible value.

Given that the trigonometric function is f(t) = 7t + [tex]7 cot\frac{t}{2}[/tex]

Also given the point at which the function has critical values= [[tex]\frac{\pi }{4} , \frac{7\pi }{2}[/tex] ]

Value of function at [tex]\frac{\pi }{4}[/tex] :

f( [tex]\frac{\pi }{4}[/tex] ) = 7( [tex]\frac{\pi }{4}[/tex] ) + 7 cot([tex]\frac{\pi }{4}.\frac{1}{2}[/tex])

=[tex]\frac{7\pi }{4}[/tex] + 7 cot ([tex]\frac{\pi }{8}[/tex])

=315 + 7 cot 22.5

=315 + 7(2.414)

= 315 + 16.898

=331.898

f( [tex]\frac{\pi }{4}[/tex] ) ≈ 331.9

Value of function at [tex]\frac{7\pi }{2}[/tex] :

f( [tex]\frac{7\pi }{2}[/tex] ) = 7( [tex]\frac{7\pi }{2}[/tex] ) + 7 cot([tex]\frac{7\pi }{2}.\frac{1}{2}[/tex])

=[tex]\frac{49\pi }{2}[/tex] + 7 cot ([tex]\frac{7\pi }{4}[/tex])

=4410 + 7 cot 315

=4410 + 7(-1)

=4410-7

=4403

f( [tex]\frac{7\pi }{2}[/tex] ) =4403

The minimum value=331.9 & maximum value is 4403

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a. for any equation containing the variables x and y, the derivative dy/dx can be found by first using algebra to rewrite the equation in the form yf(x). true or false

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The statement "For any equation containing the variables x and y, the derivative dy/dx can be found by first using algebra to rewrite the equation in the form y = f(x)." is true

For any equation containing the variables x and y, the derivative dy/dx can be found by first using algebra to rewrite the equation in the form y=f(x).
To find the derivative dy/dx, we need to have the equation in the form y = f(x).

By rewriting the equation in this form using algebra,

we can then differentiate the function f(x) with respect to x to find the derivative dy/dx.

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What is the x-coordinate of the vertex of the parabola whose equation is y = 3x2 + 9x?

A. -3
B. -[tex]\frac{2}{3}[/tex]
C. -1 [tex]\frac{1}{2}[/tex]

Answers

The x-coordinate of the vertex of the parabola whose equation is given would be -3/2. Option C.

x-coordinate calculation

To find the x-coordinate of the vertex of the parabola, we need to use the formula:

x = -b/2awhere a and b are the coefficients of the quadratic equation in standard form (ax^2 + bx + c).

In this case, a = 3 and b = 9, so:

x = -9/(2*3) = -3/2

Therefore, the x-coordinate of the vertex of the parabola is -3/2.

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The x-coordinate of the vertex of the parabola whose equation is given would be -3/2. Option C.

x-coordinate calculation

To find the x-coordinate of the vertex of the parabola, we need to use the formula:

x = -b/2awhere a and b are the coefficients of the quadratic equation in standard form (ax^2 + bx + c).

In this case, a = 3 and b = 9, so:

x = -9/(2*3) = -3/2

Therefore, the x-coordinate of the vertex of the parabola is -3/2.

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a cube has 2 faces painted red, 2 painted white, and 2 painted blue. what is the probability of getting a blue face or a red face in one roll? (enter your probability as a fraction.)

Answers

Therefore, the probability of getting a blue face or a red face in one roll is 2/3.

A cube has six faces, and we know that two of these faces are blue and two are red. Therefore, there are a total of 4 faces that are either blue or red.

To calculate the probability of getting a blue or a red face in one roll, we can use the formula:

P(blue or red) = P(blue) + P(red)

The probability of rolling a blue face is the number of blue faces divided by the total number of faces, which is 2/6, since there are 2 blue faces out of a total of 6 faces. Similarly, the probability of rolling a red face is also 2/6.

So, substituting these values into the formula, we get:

P(blue or red) = 2/6 + 2/6

= 4/6

= 2/3

Therefore, the probability of getting a blue or a red face in one roll of the cube is 2/3.

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given: σ = {a}. what is the minimum pumping length for each of the following languages: {}, {a}, {a, aaaa, aa}, σ∗ , and {ϵ

Answers

The minimum pumping length of {} is any positive integer, of {a} is 1, {a, aaaa, aa}: 1, σ∗: 1 and of {ϵ} is not regular

To find the minimum pumping length for a given language, we need to consider the smallest possible strings in the language and find the smallest length at which we can apply the pumping lemma.

{} (the empty language): There are no strings in the language, so the pumping lemma vacuously holds for any pumping length. The minimum pumping length is any positive integer.

{a}: The smallest string in the language is "a". We can choose the pumping length to be 1, since any substring of "a" of length 1 is still "a". Thus, the minimum pumping length is 1.

{a, aaaa, aa}: The smallest string in the language is "a". We can choose the pumping length to be 1, since any substring of "a" of length 1 is still "a". Thus, the minimum pumping length is 1.

σ∗ (the Kleene closure of σ): Any string over {a} is in the language, including the empty string. We can choose the pumping length to be 1, since any substring of any string in the language of length 1 is still in the language. Thus, the minimum pumping length is 1.

{ϵ} (the language containing only the empty string): The smallest string in the language is the empty string, which has length 0. However, the pumping lemma requires that the pumping length be greater than 0. Since there are no other strings in the language, we cannot satisfy the pumping lemma for any pumping length. Thus, the language {ϵ} is not regular.

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change from rectangular to cylindrical coordinates. (let r ≥ 0 and 0 ≤ ≤ 2.) (a) (−5, 5, 5) (b) (−3, 3 3 , 1)

Answers

a) Cylindrical coordinates for point (-5, 5, 5) are (r, θ, z) = (√50, 3π/4, 5).
b) Cylindrical coordinates for point (-3, 3√3, 1) are (r, θ, z) = (6, 5π/6, 1).

How to change from rectangular coordinates (x, y, z) to cylindrical coordinates (r, θ, z)?

We will use the following equations:

1. r = √(x² + y²)
2. θ = arctan(y/x) (note: make sure to take the quadrant into account)
3. z = z (z-coordinate remains the same)

(a) For the point (-5, 5, 5):

1. r = √((-5)² + 5²) = √(25 + 25) = √50
2. θ = arctan(5/-5) = arctan(-1) = 3π/4 (in the 2nd quadrant)
3. z = 5

So, the cylindrical coordinates for point (-5, 5, 5) are (r, θ, z) = (√50, 3π/4, 5).

(b) For the point (-3, 3√3, 1):

1. r = √((-3)² + (3√3)²) = √(9 + 27) = √36 = 6
2. θ = arctan((3√3)/-3) = arctan(-√3) = 5π/6 (in the 2nd quadrant)
3. z = 1

So, the cylindrical coordinates for point (-3, 3√3, 1) are (r, θ, z) = (6, 5π/6, 1).

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which of the following functions has an amplitude of 3 and a phase shift of π/2? a) f(x) = -3 cos(2x - π) + 4. b) g(x) = 3cos(2x + π) -1. c) h(x) = 3 cos (2x - π/2) + 3. d) j(x) = -2cos(2x + π/2) + 3

Answers

The function with an amplitude of 3 and a phase shift of π/2 is h(x) = 3 cos (2x - π/2) + 3.

The amplitude of a function is the distance between the maximum and minimum values of the function, divided by 2. The phase shift of a function is the horizontal shift of the function from the standard position,

(y = cos(x) or y = sin(x)).
To find the function with an amplitude of 3 and a phase shift of π/2, we need to look for a function that has a coefficient of 3 on the cosine term and a horizontal shift of π/2.
Looking at the given options, we can eliminate option a) because it has a coefficient of -3 on the cosine term, which means that its amplitude is 3 but it is inverted.

Option b) has a coefficient of 3 on the cosine term but it has a phase shift of -π/2, which means it is shifted to the left instead of to the right. Option d) has a phase shift of π/2, but it has a coefficient of -2 on the cosine term, which means its amplitude is 2 and not 3.
A*cos(B( x - C)) + D

Where A is the amplitude, B affects the period, C is the phase shift, and D is the vertical shift.

f(x) = -3 cos(2x - π) + 4

Amplitude: |-3| = 3

Phase shift: π (not π/2) b) g(x) = 3cos(2x + π) -1

Amplitude: |3| = 3

Phase shift: -π (not π/2) c) h(x) = 3 cos (2x - π/2) + 3

Amplitude: |3| = 3

Phase shift: π/2 d) j(x) = -2cos(2x + π/2) + 3200

Amplitude: |-2| = 2 (not 3)

Phase shift: -π/2
Therefore, the only option left is c) h(x) = 3 cos (2x - π/2) + 3. This function has a coefficient of 3 on the cosine term and a horizontal shift of π/2, which means it has an amplitude of 3 and a phase shift of π/2.
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Question 22
The future value, V, in dollars of an account with a monthly interest rate of i and
deposits on January 1st, February 1st and March 1st is given by the following equation
V = 50(1 + i)² + 100(1 + i) + 150. Which of the following equivalent expressions
contains the future value, as a constant or coefficient, for a monthly interest rate of
i = 0.1?
a. 50(i + 0.1)² + 190(i + 0.1) + 280.5
b. 50i² + 200i + 300
c.
50(i-0.1)² + 210(i - 0.1) + 320.5
d. 50(i + 2)² + 100

Answers

Answer:

c. 50(i-0.1)² + 210(i - 0.1) + 320.5.

Step-by-step explanation:

To find the equivalent expression that contains the future value for a monthly interest rate of i = 0.1, we simply substitute i = 0.1 into the equation V = 50(1 + i)² + 100(1 + i) + 150 and simplify.

V = 50(1 + 0.1)² + 100(1 + 0.1) + 150

V = 50(1.1)² + 100(1.1) + 150

V = 50(1.21) + 110 + 150

V = 60.5 + 110 + 150

V = 320.5

Therefore, the expression that contains the future value for a monthly interest rate of i = 0.1 is c. 50(i-0.1)² + 210(i - 0.1) + 320.5.

Problem 6-33 Consider a system having four components with reliabilities through time t of: (1) 0.80 (2) 0.66(3) 0.78 (4) 0.89

Answers

The overall reliability of the system through time t is approximately 0.370.

You have a system with four components and their reliabilities through time t are given as follows:

1. Component 1: 0.80
2. Component 2: 0.66
3. Component 3: 0.78
4. Component 4: 0.89

To find the overall reliability of the system, you'll need to multiply the reliabilities of each individual component:

Overall Reliability = Component 1 Reliability × Component 2 Reliability × Component 3 Reliability × Component 4 Reliability

Step-by-step calculation:

Overall Reliability = 0.80 × 0.66 × 0.78 × 0.89

Now, multiply the given reliabilities:

Overall Reliability ≈ 0.370

So, the overall reliability of the system through time t is approximately 0.370.

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Pls help (part 2)
Give step by step explanation!

Answers

If the "swimming-pool" for children is built with rectangular-prism and 2 halves of cylinder, then the total volume of pool is 312.64 m³.

From the figure, we observe that the swimming pool is made up of a rectangular prism, and 2 halves of cylinder,

the diameter of the half of cylinder is = 16m ,

So, radius of the half of cylinder is = 16/2 = 8m,

The volume of 2 halves of cylinder is = πr²h,

Substituting the values,

We get,

Volume of 2 halves of cylinder is = π × 8 × 8 × 0.6 ≈ 120.64 m³,

Now, the volume of the rectangular prism is = 20 × 16 × 0.6 = 192 m³,

So, the Volume of the swimming pool is = 192 + 120.64 = 312.64 m³.

Therefore, the total volume of swimming pool is 312.64 m³.

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Chris is covering a window with a decorative adhesive film to filter light. The film cost $2.35 per square root. How much will the film cost?

Answers

The cost of the film for the whole area of the figure is $73.6.

Given that,

Chris is covering a window with a decorative adhesive film to filter light.

The figure is a window in the shape of a parallelogram.

We have to find the area of the figure.

Area of parallelogram = Base × Height

Area = 8 × 4 = 32 feet²

Cost for the film per square foot = $2.3

Cost of the film for 32 square foot = 32 × $2.3 = $73.6

Hence the cost of the film is $73.6.

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There are 100 pupils in a group. The only languages available for the group study are Spanish and Russian. 30 pupils study Spanish. 54 pupils study Russian. 35 pupils study neither Spanish nor Russia. Complete the venn diagram

Answers

From the Venn diagram, the values of a, b, c and d are11,19,35,35 respectively

What is Venn diagram?

A Venn diagram is an illustration that uses circles to show the relationships among things or finite groups of things. Circles that overlap have a commonality while Circles that do not overlap do not share those traits.

The universal set is ∈ = 100

The languages are

Spanish = 30

Russian = 54

(S∪ R)¹ = 35 = d

a = Spanish only = a-b

30-b = a

Russia only = c-b

54 - b

Therefore, The universal set ∈ is

100 = (a-b) + (b)+ (c-b) +(d)

100 = 30-b + b + 54 - b + 35

100 = 119 - b = 119-100

b= 19

Therefore,

a = 30 -19 =11

b = 19

c = 59 - 19 35

d = 35

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determine whether the series is convergent or divergent. [infinity] ∑ ln (n^2 + 1) / (2n^2 + 7) n = 1 A. convergent B. divergent

Answers

The given series is convergent.

How to determine whether the series is convergent or divergent?

We will use the ratio test to determine the convergence or divergence of the given series:

r = [tex]lim_{n\rightarrow \infty} |(ln[(n+1)^2+1]/(2(n+1)^2+7)) / (ln(n^2+1)/(2n^2+7))|[/tex]

r =[tex]lim_{n\rightarrow \infty} |(ln[(n+1)^2+1]/(2(n+1)^2+7)) * ((2n^2+7)/(ln(n^2+1)))|[/tex]

r = [tex]lim_{n\rightarrow \infty} |(ln[(n+1)^2+1]/ln(n^2+1)) * (2n^2+7)/(2(n+1)^2+7)|[/tex]

We note that the expression [tex](ln[(n+1)^2+1]/ln(n^2+1))[/tex] approaches 1 as n approaches infinity. So we can simplify the above expression as:

r = [tex]lim_{n\rightarrow \infty} |(2n^2+7)/(2(n+1)^2+7)|[/tex]

Now, as n approaches infinity, the terms [tex](2n^2+7)[/tex] and [tex]2(n+1)^2+7[/tex] both approach infinity. So we can apply L'Hopital's rule to the limit:

r =[tex]lim_{n\rightarrow \infty } |(4n)/(4n+4)| = lim_{n\rightarrow \infty} |n/(n+1)| = 1[/tex]

Since the limit r is equal to 1, the ratio test is inconclusive. Therefore, we cannot determine the convergence or divergence of the given series using this test.

However, we can use the comparison test to show that the series is convergent. We note that:

[tex]ln(n^2+1) < n^2+1[/tex] for all n >= 1

So we have:

[tex]ln(n^2+1)/(2n^2+7) < (n^2+1)/(2n^2+7)[/tex]

Since the series ∑ [tex](n^2+1)/(2n^2+7)[/tex] converges by the limit comparison test with the series ∑ [tex]1/n^2[/tex], the series ∑ [tex]ln(n^2+1)/(2n^2+7)[/tex] is also convergent by the comparison test.

Therefore, the given series is convergent.

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