4. An Internet provider contacts a random sample of 300 customers and asks how many hours per week the customers use the Internet. It found the average amount of time spent on the Internet per week to be about 7.2 hours. a) A bootstrap sample of size 300 (the same size as the original sample) would be generated by sampling from the original sample with replacement. The standard error is about 0.458. Find and interpret a 95% confidence interval for the parameter. Round the margin of error to two decimal places. (4 pts) b) Percentiles of the bootstrap distribution are provided. Use the percentiles to report a 90% confidence interval for the parameter. (2 pts) 1% 2.5% 5% 10% 25% 50% 75% 90% 95% 97.5% 99% 6.17 6.32 6.44 6.59 6.86 7.17 7.48 7.78 7.94 8.08 8.30
Added by Courtney H.
Close
Step 1
First, we need to find the standard error of the parameter. Show more…
Show all steps
Your feedback will help us improve your experience
Lucas Finney and 89 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
[16 points] An Internet provider contacts a random sample of 300 customers and asks how many hours per week the customers use the Internet. It found the average amount of time spent on the Internet per week of the sample participants to be 7.2 hours. The standard error is 0.458. (a) Find the margin of error, using the given standard error, for a 99% confidence interval for the average amount of time all customers use the Internet. (b) Use the result of part (a) to find the 99% confidence interval for the parameter. Round to two decimal places and show work. (c) Interpret the confidence interval you obtained in part (b) in an English sentence in the context of the situation. (d) A claim is made that the average amount of time spent on the Internet per week is not 7 hours. Give the null and alternate hypotheses used in a test of this claim.
Sri K.
Step 1 of 3: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places. Land's Bend sells a wide variety of outdoor equipment and clothing. The company sells both through mail order and via the internet. Random samples of sales receipts were studied for mail-order sales and internet sales, with the total purchase being recorded for each sale. A random sample of 66 sales receipts for mail-order sales results in a mean sale amount of $83.00 with a standard deviation of $20.25. A random sample of 11 sales receipts for internet sales results in a mean sale amount of $72.60 with a standard deviation of $23.75. Using this data, find the 95% confidence interval for the true mean difference between the mean amount of mail-order purchases and the mean amount of internet purchases. Assume that the population variances are not equal and that the two populations are normally distributed.
Wei Z.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD