1. (20 pts.) How much do students pay, on the average, for textbooks during the first semester of college? From a random sample of 400 students the mean cost was found to be $357.75, and the sample standard deviation was $37.89. Assuming that the population is normally distributed, find the margin of error of a 91% confidence interval for the population mean.
Added by Monica J.
Close
Step 1
We are given a sample mean ($\bar{x}$) of $357.75, a sample standard deviation (s) of $37.89, and a sample size (n) of 400. Show more…
Show all steps
Your feedback will help us improve your experience
Adi S and 71 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
For a random sample of 400 students, the mean cost for textbooks during the first semester of college was found to be $355.75, and the sample standard deviation was $35.28. Assuming that the population is normally distributed, find the margin of error of a 95% confidence interval for the population mean. The margin of error for a 95% confidence interval is
Anna D.
For a random sample of 400 students, the mean cost for textbooks during the first semester of college was found to be 374.75 $, and the sample standard deviation was 35.48 $. Assuming that the population is normally distributed, find the margin of error of a 90% confidence interval for the population mean. The margin of error for 90% confidence interval is nothing. (Round to two decimal places as needed.)
Ahmet Y.
2. How much, on average, do full-time students pay for textbooks for a semester? Below is a random sample of the textbook costs of 25 full-time students: Data: 250, 275, 233, 175, 275, 325, 158, 265, 185, 205, 218, 125, 310, 195, 200, 245, 215, 172, 200, 275, 187, 225, 145, 150, 300. a) We wish to produce a 90% confidence interval for the mean cost (whose . value is unknown to us) of textbooks for all full-time students. Interpret b) Draw the histogram to see if your data follows a normal distribution.
Adi S.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD