Based on a sample of 180 textbooks at the store, you find an average of 71.51 and a standard deviation of 17. The point estimate is: The 99% confidence interval is: (to 3 decimals) to (to 3 decimals)

Find the following. Enter your answer rounded to at least two decimals. z a/2 for the 97% confidence interval

Find the following. Enter your answer rounded to at least two decimals. Z(a/2) for the 95% confidence interval

SAT Scores are distributed with a mean of 1,500 and a standard deviation of 300. You are interested in estimating the average SAT score of first year students at your college. If you would like to limit the margin of error of your 95% confidence interval to 25 points, how many students should you sample?

A random sample of 64 shoppers showed that they spend an average of $27.31 per visit at the Sunday Mornings Bookstore. The standard deviation of the population is $2.14. Find the 90% confidence interval of the true mean. Please include all work showing how you found your answer.

Karen wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 78 cookies and finds that the number of chocolate chips per cookie in the sample has a mean of 19.3 and a standard deviation of 2.1.   Find a 80% confidence interval for the number of chocolate chips per cookie for Big Chip cookies?   Round your answers to one decimal place.