Question

Professors in the Economics Department at Western want to determine how challenging the program was for...

Professors in the Economics Department at Western want to determine how challenging the program was for students. Out of a random sample of 21 students, 16 indicated that the program was either "challenging" or "very challenging". The 95% confidence interval estimating the proprotion of all students in the department who thought the program was challenging is given by which of the following?

Question 9 options:

1)

( 0.60903 , 0.91478 )

2)

( -0.57974 , 0.94407 )

3)

( 0.66896 , 0.85485 )

4)

( 0.57974 , 0.94407 )

5)

( 0.05593 , 0.42026 )

Question 10 (1 point)

A local pizza place claims that they average a delivery time of 6.33 minutes. To test this claim, you order 15 pizzas over the next month at random times on random days of the week. You calculate that the average delivery time is 8.99 minutes with a standard deviation of 1.268 minutes. You create a 95% confidence interval of (8.29, 9.69). Of those listed below, what is the best conclusion you can make?

Question 10 options:

1)

We cannot determine the proper interpretation based on the information given.

2)

The average delivery time does not significantly differ from 6.33 minutes.

3)

You are 95% confident that the average delivery time is less than 6.33 minutes.

4)

The percentage of pizzas that arrive around 6.33 minutes is 95%.

5)

You are 95% confident that the average delivery time is greater than 6.33 minutes.

Homework Answers

Answer #1

1)

sample proportion = 16 / 21 = 0.7619

95% Confidence interval for p is

- Z * sqrt( ( 1 - ) / n) < p < + Z * sqrt( ( 1 - ) / n)

0.7619 - 1.96 * sqrt( 0.7619 * 0.2381 / 21) < P < 0.7619 + 1.96 * sqrt( 0.7619 * 0.2381 / 21)

0.57974 < p < 0.94407

95% CI is (0.57974 , 0.94407 )

2)

Since 6.33 not contained in confidence interval, we have sufficient evidence to reject null hypothesis.

We conclude that,

You are 95% confident that the average delivery time is greater than 6.33 min

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A local pizza place claims that they average a delivery time of 7.32 minutes. To test...
A local pizza place claims that they average a delivery time of 7.32 minutes. To test this claim, you order 11 pizzas over the next month at random times on random days of the week. You calculate the average delivery time and sample standard deviation from the 11 delivery times (minutes), and with the sample mean and sample standard deviation of the time (minutes), you create a 95% confidence interval of (7.648, 9.992). (delivery time is normally distributed) a. What...
A customer wants to estimate the average delivery time of a pizza from the local pizza...
A customer wants to estimate the average delivery time of a pizza from the local pizza parlor. The customer wants to obtain a sample mean that falls within 3.212 minutes of the true average delivery time with 90% confidence. If the customer knows the standard deviation of the delivery times of all pizzas is 11.959, how many pizzas will need to be ordered? Question 6 options: 1) We do not have enough information to answer this question since we were...
John Pizza Restaurant is facing a stiff competition from the new competing pizza restaurant guaranteeing pizza...
John Pizza Restaurant is facing a stiff competition from the new competing pizza restaurant guaranteeing pizza deliveries within 32 minutes or the pizza is given free. To answer this challenge, Maldini wants to offer a 30-minute delivery guarantee. After a careful cost analysis, Maldini has determined that such a guarantee would require an average delivery time of less than 27 minutes. She thought that this would limit the percentage of ‘free pizzas’ under the guarantee to less than 8% of...
Suppose you are interested in measuring the amount of time, on average, it takes you to...
Suppose you are interested in measuring the amount of time, on average, it takes you to make your commute to school. You've estimated that the average time is 39 minutes with a standard deviation of 5.611 minutes. Assuming that your estimated parameters are correct and the commute time is normally distributed, what is the probability that the average commute time of 12 random days is greater than 40.72 minutes? 1) 0.8598 2) 0.1441 3) 0.3796 4) 0.8559 5) 0.6204 A...
Suppose you are a civil engineer, specializing in traffic volume control for the City of Grand...
Suppose you are a civil engineer, specializing in traffic volume control for the City of Grand Rapids. Your department has been receiving a multitude of complaints about traffic wait times for a certain intersection in the heart of downtown. To see if these claims are valid, you want to monitor the true average wait time at that intersection. Over the course of a few months, you record the average number of minutes a car waits at the intersection between 4:00...
You want to determine the percentage of seniors who drive to campus. You take a random...
You want to determine the percentage of seniors who drive to campus. You take a random sample of 125 seniors and ask them if they drive to campus. Your 95% confidence interval turns out to be from 0.69 to 0.85. Select each correct interpretation of this situation. There might be no, one, or more than one correct statement. Explain, the reason if it is not a correct interpretation. 77% of the seniors in your sample drive to campus. 95% of...
The owner of a local phone store wanted to determine how much customers are willing to...
The owner of a local phone store wanted to determine how much customers are willing to spend on the purchase of a new phone. In a random sample of 10 phones purchased that day, the sample mean was $473.426 and the standard deviation was $29.1709. Calculate a 95% confidence interval to estimate the average price customers are willing to pay per phone. Question 1 options: 1) ( 452.558 , 494.294 ) 2) ( -452.558 , 494.294 ) 3) ( 464.201...
5. How heavy are the backpacks carried by college students? To estimate the weight of backpacks...
5. How heavy are the backpacks carried by college students? To estimate the weight of backpacks carried by college students, a researcher weighs the backpacks from a random sample of 58 college students. The average backpack weight ends up being 15.7 pounds, with a standard deviation of 2.4 pounds. If you use this data to construct a 90% confidence interval, what will the margin of error be for this interval? Try not to do a lot of intermediate rounding until...
Recently, commuters in Minneapolis have protested on social media, saying commuting time has increased due to...
Recently, commuters in Minneapolis have protested on social media, saying commuting time has increased due to a number of badly-designed construction projects on main roads into and out of the city. A random sample of 72 commuters revealed an average commuting time of 46.8 minutes with a standard deviation of 6.90 minutes. If you were to calculate a 95% confidence interval, what value would you use for the critical value t*? Question 12 options: 1.645 1.993 1.994 1.96 Question 13...
1. The average number of minutes spent per day using social media by a population of...
1. The average number of minutes spent per day using social media by a population of college sophomores is 29.6 minutes. If we take a random sample of size n = 87 from this population and find that the sample standard deviation is 7.3 minutes, we know the sampling distribution of the sample mean in this case would have a standard deviation equal to A. 4.05 minutes. B. 1.60 minutes. C. 0.78 minutes. D. 7.30 minutes. E. 3.17minutes. 2. Return...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT