# Question: In Example 7 5 we calculated a 95 confidence interval estimate

In Example 7.5 we calculated a 95% confidence interval estimate of the Healthy Eating Index-2005 score for a random sample of participants at the time of their first interview. Recall that there are two observations for each person in the study. The first observation, identified by daycode = 1, contains data from the first interview and the second observation, daycode = 2, contains data from the second interview. Find a 95% confidence interval for the mean HEI-2005 score for participants at the time of their second interview. The data are stored in the data file HEI Cost Data Variable Subset.

**View Solution:**## Answer to relevant Questions

A machine that packages 18-ounce (510-gram) boxes of sugar-coated wheat cereal is being studied. The weights for a random sample of 100 boxes of cereal packaged by this machine are contained in the data file Sugar. a. Find a ...A car-rental company is interested in the amount of time its vehicles are out of operation for repair work. State all assumptions and find a 90% confidence interval for the mean number of days in a year that all vehicles in ...The Mendez Mortgage Company case study was given in Chapter 2. A random sample of n = 350 accounts of the company's total portfolio was selected. Estimate the proportion of all the company's accounts with an original ...Find the lower confidence limit for the population variance for each of the following normal populations. a. n = 21; a = 0.05; s2 = 16 b. n = 16; a = 0.05; s = 8 c. n = 28; a = 0.01; s = 15 A manufacturer bonds a plastic coating to a metal surface. A random sample of nine observations on the thickness of this coating is taken from a week's output, and the thicknesses (in millimeters) of these observations are ...Post your question