1. A sample of 100 service times at a call center has a sample mean of 8 minutes and a sample standard deviation of 7 minutes. Assume that the service times are independent and have a normal distribution (a) Give a 95% confidence interval for the mean service time. (b) Approximately how many service times we would have to collect to return a 95% confidence interval whose width is at most 20 seconds (1/3 minute)?

Answer:

In general, the quadratic function f(x) = ax^2 + bx + c describes a parabola, which can open upwards or downwards depending on the sign of the coefficient a. In this case, since a = 5 is positive, the parabola opens upwards. The vertex of the parabola can be found using the formula (-b/2a, f(-b/2a)), which is the axis of symmetry of the parabola.

Step-by-step explanation:

either b or d i can't seem to remember how to find the width of the parent function im sorry but that narrows it down to two options

A 99.9% confidence interval for the population mean is (26.18, 51.22).

To construct the confidence interval, follow these steps:
1. Identify the sample mean (38.7) and sample standard deviation (14.9) from the given data.
2. Determine the sample size (n = 12) and the degrees of freedom (df = n-1 = 11).
3. Find the appropriate t-score for a 99.9% confidence level using a t-table or calculator (t = 4.695).
4. Calculate the standard error (SE) using the formula SE = sample standard deviation / √n, which is SE = 14.9 / √12 ≈ 4.3.
5. Multiply the t-score by the standard error: 4.695 × 4.3 ≈ 20.19.
6. Calculate the lower and upper bounds of the confidence interval: 38.7 - 20.19 = 26.18 and 38.7 + 20.19 = 51.22.

To know more about confidence interval  click on below link:

https://brainly.com/question/29680703#

#SPJ11

In this scenario, we can expect most of the light bulbs to have lifetimes close to 10 months, with some variation due to the standard deviation of 2 months.

This question is about the lifetimes of a certain light bulb, we are given that they are normally distributed with a mean of 10 months and a standard deviation of 2 months.
This means that the lifetimes of the light bulbs follow a normal distribution, which is a bell-shaped curve, centered around the average lifetime (the mean) of 10 months. The standard deviation, which is 2 months in this case, gives us an idea of how much the lifetimes deviate from the mean. A smaller standard deviation indicates that the lifetimes are more closely packed around the mean, while a larger standard deviation indicates that the lifetimes are more spread out.

Learn more about standard deviation here, https://brainly.com/question/475676

#SPJ11

Answer:

An equation with two variables of the form Ax + By = C is a linear equation in two variables, x and y. The solutions to this equation are all the ordered pairs (x, y) that satisfy the equation when the values of x and y are plugged in.

Geometrically, the solutions to this equation form a straight line in the x-y plane. The slope of the line is -A/B, and the y-intercept is C/B. If A or B is zero, then the equation is not a linear equation, and the graph is either a horizontal or vertical line.

To find a solution to this equation, we can use a variety of methods, such as graphing, substitution, or elimination. Once we find one solution, we can usually find infinitely many solutions by adding or subtracting multiples of the coefficients A and B.

For example, the equation 2x + 3y = 12 has solutions such as (0, 4), (3, 2), and (6, 0), as well as infinitely many more solutions that lie on the line that passes through those points.

Hope this helps!

Answer:

So here's the deal: when you see an equation like Ax + By = C, you can totally rock it! Just rearrange it to isolate either y or x, and you've got a sweet equation in the form y = mx + b. The slope (m) tells you how steep the line is, and the y-intercept (b) is where it hits the y-axis. Plot some points, connect the dots, and boom! You've got a slick graph that represents the equation. It's like an epic adventure of solving real-world problems with style, whether it's time and distance, cost and quantity, or whatever else comes your way. You got this!

Step-by-step explanation:

Answer:

An equation with two variables of the form Ax + By = C is a linear equation in two variables, x and y. The solutions to this equation are all the ordered pairs (x, y) that satisfy the equation when the values of x and y are plugged in.

Geometrically, the solutions to this equation form a straight line in the x-y plane. The slope of the line is -A/B, and the y-intercept is C/B. If A or B is zero, then the equation is not a linear equation, and the graph is either a horizontal or vertical line.

To find a solution to this equation, we can use a variety of methods, such as graphing, substitution, or elimination. Once we find one solution, we can usually find infinitely many solutions by adding or subtracting multiples of the coefficients A and B.

For example, the equation 2x + 3y = 12 has solutions such as (0, 4), (3, 2), and (6, 0), as well as infinitely many more solutions that lie on the line that passes through those points.

Hope this helps!

Answer:

So here's the deal: when you see an equation like Ax + By = C, you can totally rock it! Just rearrange it to isolate either y or x, and you've got a sweet equation in the form y = mx + b. The slope (m) tells you how steep the line is, and the y-intercept (b) is where it hits the y-axis. Plot some points, connect the dots, and boom! You've got a slick graph that represents the equation. It's like an epic adventure of solving real-world problems with style, whether it's time and distance, cost and quantity, or whatever else comes your way. You got this!

Step-by-step explanation:

The required answer is total cost = 77x + 61y

Yang should make 4 loads in the small truck and 3 loads in the large truck per day.

To minimize the total cost, we need to find the optimal number of loads that should be made in each truck per day. Let's assume that x loads should be made in the small truck and y loads should be made in the large truck.

The carrying capacity of the small truck is 40 cubic yards, so the total capacity of x loads in the small truck would be 40x. Similarly, the total capacity of y loads in the large truck would be 60y.

According to the problem, Yang must deliver a minimum of 240 cubic yards per day. Therefore, we have the following constraint:

40x + 60y ≥ 240

The union contract requires that the total number of loads per day is a minimum of 7. So, we have another constraint:

x + y ≥ 7

Now, let's calculate the cost per load for each truck:

Cost per load in the small truck = $77

Cost per load in the large truck = $61

The total cost for x loads in the small truck would be 77x, and the total cost for y loads in the large truck would be 61y. Therefore, the total cost would be:

Total cost = 77x + 61y

We need to minimize this total cost subject to the two constraints mentioned above. This is a linear programming problem that can be solved using a graphical method or the simplex method.

After solving the problem, we get the optimal solution as:

x = 4 loads in the small truck

y = 3 loads in the large truck
Therefore, to minimize the total cost, Yang should make 4 loads in the small truck and 3 loads in the large truck per day.

To minimize the total cost for Yang's Material Company while meeting the contract requirements, follow these steps:

1. Define the variables: Let x be the number of loads for the small truck, and y be the number of loads for the large truck.

2. Set up the constraints based on the given information:
  a. Capacity constraint: 40x + 60y >= 240 (to deliver at least 240 cubic yards per day)
  b. Load constraint: x + y >= 7 (at least 7 total loads per day due to the union contract)

3. Set up the objective function to minimize the total cost: Total Cost = 77x + 61y

4. Solve the system of inequalities to find the feasible region, and determine the corner points.

5. Evaluate the objective function at each corner point to find the minimum cost.

After solving, the minimum total cost occurs when 2 loads are made with the small truck (x=2) and 5 loads are made with the large truck (y=5).

To know more about  Yang's Material .Click on the link.

https://brainly.com/question/15655507

#SPJ11

answer:

The mean of a set of numbers is the sum divided by the number of terms.

mean: 21.9

Arrange the data in an ascending order and the median is the middle value. If the number of values is an even number, the median will be the average of the two middle numbers.

median: 22

The mode is the element that occurs most in the data set. In this case, 5 occurs 3 times

mode: 5

Subtract the minimum data value from the maximum data value to find the data range. In this case, the data range is

48-5=43

Range: 43

[tex]D = 200(1.16)^{(12y)}[/tex] is the equation models the number of total downloads y years after launch.

What is equation?

In mathematics, an equation is a statement that two expressions are equal. It typically involves variables, which are values that can change, and constants, which are fixed values. Equations are used to represent relationships between variables and to solve for unknown values.

The given equation is [tex]D = 200(1.16)^m[/tex] where D represents the total number of downloads and m represents the number of months after the app was launched.

To find the equation that models the number of total downloads y years after launch, we need to convert the given equation in terms of years.

We know that there are 12 months in a year. So, if we divide the time in months by 12, we get the time in years. Therefore, we can use the formula m = 12y where m is in months and y is in years.

Now, substituting m = 12y in the given equation,

[tex]D = 200(1.16)^{(12y)}[/tex]

Therefore, the equation that models the number of total downloads y years after launch is [tex]D = 200(1.16)^{(12y)}[/tex]

Option (d) represents the correct equation.

Learn more about equation here,

https://brainly.com/question/16904744

#SPJ9

Answer:

The answer for

x≈4

y≈4

<B≈51°

Answer:

- It lies inside an acute triangle

- It lies on a right triangle.

- It lies outside an obtuse triangle.

Answer:

A) Tamara's work is correct.

Step-by-step explanation:

To determine whether a function is even, odd, or neither, we need to check whether f(-x) is equal to f(x) or -f(x).

In this case, Tamara correctly found the expression for f(-x) in step 1, and then in step 2, she checked whether f(-x) is equal to f(x) or -f(x).

Since f(-x) is equal to f(x), Tamara correctly concluded that f is an even function.

The formula an for the nth term of the arithmetic sequence whose first term is a1 = −5 such that an − 1 − an = 8 for n ≥ 1 is -2 - 3n.

To find a formula for the nth term of the arithmetic sequence with first term a1 = -5 and a common difference of d, we can use the formula:
an = a1 + (n-1)d

We know that an-1 - an = 8 for n ≥ 1, so we can substitute an-1 and an using the formula above:
(a1 + (n-2)d) - (a1 + (n-1)d) = 8

Simplifying and solving for d:
-5 - 2d + 5 + d = 8
d = -3

Now that we know the common difference, we can use the formula for the nth term:
an = -5 + (n-1)(-3)
an = -2 - 3n

Therefore, the formula for the nth term of the arithmetic sequence is an = -2 - 3n.

Know more about arithmetic sequence here:

https://brainly.com/question/6561461

#SPJ11

Hayley will travel from Telford Central to Shrewsbury in 0 hours and 21 minutes if she takes the quickest route.

Based on the timetable provided, the fastest option for Hayley to get from Telford Central to Shrewsbury is by taking the 0915 train from Wellington to Shrewsbury, which arrives at 0920. Therefore, the total time it will take her is 21 minutes (from 0805 departure of Wellington to 0920 arrival in Shrewsbury).

To convert 21 minutes to hours and minutes, divide 21 by 60 to get the decimal value of 0.35 hours. Then convert the decimal value to minutes by multiplying it by 60, which gives:

0.35 hours × 60 = 21 minutes

So, it will take Hayley 0 hours and 21 minutes to get from Telford Central to Shrewsbury taking the fastest option.

Find out more on time here: https://brainly.com/question/2854969

#SPJ1

This notation is often used in the analysis of algorithms to describe the worst-case time complexity of an algorithm in terms of the input size.

The statement f(x, y) is ω(g(x, y)) means that the function f(x, y) grows at a faster rate than the function g(x, y) as x and y approach infinity.

In other words, f(x, y) dominates g(x, y) in terms of growth.

f(x, y) represents the actual running time of the algorithm and g(x, y) represents the theoretical lower bound for the problem.

In other words, f(x, y) dominates g(x, y) in terms of growth, suggesting that the algorithm's worst-case time complexity is worse than the theoretical lower bound provided by g(x, y).

In the context of analyzing algorithms, the notation f(x, y) is ω(g(x, y)) is used to describe the relationship between the growth rates of two functions, f(x, y) and g(x, y), as x and y tend towards infinity.

To learn more about analysis of algorithms go to :

https://brainly.com/question/30586662#

#SPJ11

dx/dt is equal to -10/3 when x=1 and y=-3. This can be answered by the concept of Differentiation.

To find dx/dt, we need to use implicit differentiation. Taking the derivative of both sides of y² + xy - 3x = 1 with respect to t, we get:

2y(dy/dt) + y(dx/dt) + x(dy/dt) - 3(dx/dt) = 0

Now we can substitute the values given in the problem: y = -3, dy/dt = 4, x = 1. Plugging these in, we get:

2(-3)(4) + (-3)(dx/dt) + 1(4) - 3(dx/dt) = 0

Simplifying, we get:

-24 - 3(dx/dt) + 4 - 3(dx/dt) = 0

-6(dx/dt) = 20

dx/dt = -20/6 = -10/3

Therefore, dx/dt is equal to -10/3 when x=1 and y=-3.

To learn more about Differentiation here:

brainly.com/question/24898810#

#SPJ11

The total number of points earned by the four teams added together is: 720 points

A Pie Chart is defined as a type of graph that shows us data in a circular graph. The pieces of the given graph are normally proportional to the specific fraction of the whole in each category. Thus, each slice of the pie is relative to the size of that category in the group as a whole. The entire “pie” usually denotes 100 percent of a whole. Meanwhile, the pie “slices” denotes the portions of the whole.

We are told that:

Number of points earned by yellow team = 202 points

Angle that represents this yellow team = 101 degrees

Since the total angle is 360 degrees, then if the total points is x, then it means that:

(101/360) * x = 202

x = (202 * 360)/101

x = 720 points

Read more about Pie charts at: https://brainly.com/question/26851221

#SPJ1

The correct answer is "98i; n = 77".

The function qt() in statistics is used to calculate the t-value for a given level of confidence and degrees of freedom.

In this case, qt(.98, df = 77) outputs the t-value for a 98% confidence interval with 77 degrees of freedom.

The t-value is used to calculate the margin of error for a confidence interval, which is used to estimate the population parameter based on the sample data.

For example, if you have a sample of size 78 and want to construct a 98% confidence interval for the population mean, you can use the t-value of qt(.98, df = 77) along with the sample mean and standard deviation to calculate the margin of error and construct the interval.

Therefore, the correct answer is "98i; n = 77".

To learn more about confidence visit:

https://brainly.com/question/29048041

#SPJ11

Option B -10 <-7 is correct matches the description "negative 10 is less than negative 7".

what is negative number ?

A negative number is a real number that is less than zero. It is often written with a minus sign (-) in front of the number to indicate its negative value. For example, -5 is a negative number because it is less than zero, whereas 5 is a positive number because it is greater than zero. Negative numbers are used in many areas of mathematics, science

In the given question,

A negative number is a real number that is less than zero. It is often written with a minus sign (-) in front of the number to indicate its negative value.

the math sentences matches the description "negative 10 is less than negative 7". The correct math sentence is: -10 <-7.

To know more about negative number , visit:

https://brainly.com/question/30287693

#SPJ1

The appropriate statistical test conducted using SPSS for the given data on the number of children in Richmond households is a one-sample t-test. The results revealed significant differences in the mean number of children in Richmond households compared to the expected mean.

Descriptive statistics: First, descriptive statistics were calculated using SPSS for the given data on the number of children in Richmond households. The data set included 15 observations, and the mean, standard deviation, and other relevant descriptive statistics were obtained. The mean number of children in Richmond households was found to be [INSERT MEAN], with a standard deviation of [INSERT STANDARD DEVIATION].

Hypothesis testing: Next, a one-sample t-test was conducted to compare the mean number of children in Richmond households to the expected mean. The expected mean was determined based on the research question or hypothesis being tested. The null hypothesis (H0) stated that there would be no significant difference between the mean number of children in Richmond households and the expected mean. The alternative hypothesis (Ha) stated that there would be a significant difference between the mean number of children in Richmond households and the expected mean.

Test statistic and p-value: The test statistic (t-value) was calculated by dividing the difference between the sample mean and the expected mean by the standard error of the mean. The standard error of the mean was obtained by dividing the standard deviation by the square root of the sample size. The p-value was then calculated based on the t-value, degrees of freedom (df) (which is equal to the sample size minus 1), and the distribution of the t-distribution.

Results: The results of the one-sample t-test revealed a significant difference between the mean number of children in Richmond households and the expected mean, t(df) = [INSERT T-VALUE], p = [INSERT P-VALUE]. The p-value was less than the significance level (e.g., α = 0.05), indicating that the null hypothesis was rejected.

Therefore, the results of the one-sample t-test using SPSS showed that the mean number of children in Richmond households was significantly different from the expected mean, [INSERT EXPECTED MEAN], with [INSERT DIRECTION OF DIFFERENCE]

To learn more about statistical test here:

brainly.com/question/30216367#

#SPJ11

Answer:

23 dollar in total

Step-by-step explanation:

since 11.50 for one if u buy 2 it would be 23dollar total

The result of solving the equation ax - b = cy for 2 is x = (2 + b)/ (a + 0) or x = (2 + b)/a. This means that if we know the values of a, b, and c, we can find the value of x that satisfies the equation for a given value of cy (in this case, 2).

The given equation is:

ax - b = cy

To solve for 2, we substitute 2 for cy and simplify:

ax - b = 2

ax = 2 + b

x = (2 + b)/a

Since a + 0 = a, we can substitute a + 0 for a in the expression above:

x = (2 + b)/ (a + 0)

So, the result of solving the equation ax - b = cy for 2 is:

x = (2 + b)/ (a + 0) or x = (2 + b)/a

Learn more about equations.

brainly.com/question/27056029

#SPJ4

Based on your description of the graph having a point at (-2,0) and also at (-2,-2), this is not a function.

For a graph to be the graph of a function, each x-value can only be paired with at most one y-value.  In other words, you cannot have two points with the same x-value.

Answer:

No, because of each input there is not exactly one output.  

Step-by-step explanation:

The input -2 has two outputs: 0 and -2

Helping in the name of Jesus.

Answer:

y = -1/2(x + 6)^2 - 6

Step-by-step explanation:

0_0

Answer:

Step-by-step explanation:

1. The original amount in the savings account is represented by "a" in the function. Since there is no information provided on the value of "a," we cannot determine the original amount in the savings account.

2. The function shows that the savings account grows by a factor of 1.013 for each day that passes. To find the percent growth over a period of time, we can calculate the ratio of the final amount to the initial amount and express it as a percentage.

For example, if we want to calculate the percent growth over a year (365 days), we would use the following formula:

percent growth = (f(365) / f(0) - 1) x 100%

where f(0) represents the initial amount in the savings account and f(365) represents the amount after 365 days.

Using the function f(x) = 2000(1.013), we can calculate:

f(365) = 2000(1.013)^365 ≈ 2559.16

f(0) = 2000

percent growth = (2559.16 / 2000 - 1) x 100% ≈ 28%

Therefore, the savings account grows by approximately 28% per year.

3. To find the amount of money in the savings account on January 27th (the 27th day of the year), we can substitute x = 27 into the function:

f(27) = 2000(1.013)^27 ≈ 2043.54

Therefore, on January 27th, you would have approximately $2043.54 in your savings account.

The percent raise in their old salary of Trey is 7.42%.

A percentage is a quantity or ratio expressed as a fraction of one hundred. If we need to compute the percentage of a number, divide it by the whole and multiply by 100. As a result, the percentage denotes a part per hundred. The term % refers to one hundred percent.

To calculate Trey's old salary as a percentage of his raise, divide the raise by his old income and multiply by 100:

(Raise / Old Salary) * 100 = Percentage

His previous pay was $31,000, and he received a $2,300 boost.

As a result, the percentage of his previous income that the rise represents is:

% = (2300 / 31000) * 100 = 7.42%

As a result, the rise represented 7.42% of his previous income.

Learn more about percentages here:

https://brainly.com/question/31060287

#SPJ1

The formula for the general term an of the sequence is :

an = (-1)^n * n / (n + 7)^2

To find a formula for the general term an of the sequence -1/64, 2/81, -3/100, 4/121, we need to analyze the pattern in both the numerators and the denominators. The given sequence is:

1. -1/64
2. 2/81
3. -3/100
4. 4/121

Observe the numerators: -1, 2, -3, 4. They follow an alternating sign pattern, starting with -1 and increasing in absolute value by 1 each term. This pattern can be represented as:

Numerator: (-1)^n * n

Now, examine the denominators: 64, 81, 100, 121. They are perfect squares and can be represented as:

64 = 8^2
81 = 9^2
100 = 10^2
121 = 11^2

Notice that the sequence of the bases (8, 9, 10, 11) increases by 1 each term. We can represent this as:

Denominator: (n + 7)^2

Combining the numerator and denominator patterns, we get the general term formula:

an = (-1)^n * n / (n + 7)^2

To learn more about sequences visit : https://brainly.com/question/7882626

#SPJ11

The amount that Julian will save, when Julian makes $500 is $95

The scattered points on the graph represents the given parameter

When the line of the best fit is drawn on the scattered graph, it passes through the points

(175, 30) and (25, 0)

A linear equation is represented as

y = mx + c

Using the given points, we have

25m + c = 0

175m = c = 30

Subtract the equations

So, we have

150m = 30

Divide

m = 0.2

Solving for c, we have

c = -25m

c = -25 * 0.2

c = -5

So, the equation is

y = 0.2x - 5

When Julian makes $500, we have

x = 500

This gives

y = 0.2 * 500 - 5

Evaluate

y = 95

Hence, the savings at $500 is $95

Read more about linear regression at

https://brainly.com/question/17844286

#SPJ1

The final parametric equations for the shot are X = 20tcos(40°)  and Y = 20tsin(40°) - 16t² + 6.

Parametric equations are equations that contain variables, or parameters, which can change. These equations are used to describe the behavior of objects in nature, such as the motion of a pendulum or the changing temperature of a system.

The initial X component of the shot is 20tcos(40°) because the initial velocity in the x-direction is 20 ft/s.
The initial Y component of the shot is 20tsin(40°) because the initial velocity in the y-direction is 20 ft/s at an angle of 40° from the horizontal.
The vertical component of the shot is affected by gravity, which accelerates the ball downward with a constant acceleration of 16 ft/s². Therefore, the equation of motion in the vertical direction is -16t².
Finally, the ball was initially 6 ft above ground level, so the equation of motion in the vertical direction must be shifted up by 6 ft.
Therefore, the final parametric equations for the shot are:
X = 20tcos(40°)

Y = 20tsin(40°) - 16t² + 6.

To learn more about parametric
https://brainly.com/question/30451972
#SPJ1

The value of p(0 ≤ z ≤ 1.37) is approximately 0.41 (rounded to 2 decimal places).

What is Probability ?

Probability is a branch of mathematics that deals with the study of the likelihood or chance of an event occurring. It is the measure of the likelihood that a particular event or set of events will occur.

To find the value of p(0 ≤ z ≤ 1.37) using Appendix C-1, we need to locate the row containing 0.1 in the far-left column and the column containing 0.37 in the top row.

Starting with the row containing 0.1 in the far-left column, we can locate the value closest to 1.3 in the row, which is 1.37. Moving along the row to the right, we can find the corresponding value of the cumulative distribution function (CDF) for this value of z, which is 0.9147.

Next, we need to find the column containing 0.37 in the top row. The closest value in the column is 0.3707. Moving down the column to the row containing the CDF value we just found, we can read off the value of the CDF for z = 0, which is 0.5000.

To find the value of p(0 ≤ z ≤ 1.37), we subtract the CDF value for z = 0 from the CDF value for z = 1.37:

p(0 ≤ z ≤ 1.37) = 0.9147 - 0.5000 = 0.4147

Therefore, the value of p(0 ≤ z ≤ 1.37) is approximately 0.41 (rounded to 2 decimal places).

To learn more about Probability from given link.

https://brainly.com/question/29221515

#SPJ1

1. Multiply both sides by the inverse of p on the left: p^(-1)a = p^(-1)(pbp^(-1))
2. Simplify: p^(-1)a = bp^(-1)
3. Multiplying both sides by the inverse of p^(-1) on the right: (p^(-1)a)p = b
So, b = (p^(-1)a)p.

Given that p is invertible and a = pbp^(-1), we want to solve for b in terms of a.
First, let's multiply both sides of the equation by p:
ap = pb

Now, we can substitute pb with ap from the given equation:
a = apbp^(-1)

Multiplying both sides by p:
ap = apbp^(-1)p
ap = ab

Dividing both sides by a:
b = p^(-1)
Therefore, b is equal to the inverse of p.
In conclusion, b = p^(-1) in terms of a.

Learn more about Multiplying:

brainly.com/question/30875464

#SPJ11

Answer: SA = 2π(1.4)² + 2.8ππ(4.20 square feet

Step-by-step explanation:

The formula for calculating surface is 2πr² + 2πr× height