# Calculation of Mean and Standard Deviation

21. How do grocery costs compare across the country? Using a marker basket of 10 items including meat, milk, bread, eggs, coffee, potatoes, cereal, and orange juice, Where to Retire magazine calculated the cost of the market basket in six cities and in six retirement areas across the country (where to Retire). November/December 2003). The data with market basket cost to the nearest dollar are as follows:

CITY COST ($) RETIREMENT AREA COST ($)

Buffalo, Ny 33 Biloxi-Gulfport, MS 29

Des Moines, IA 27 Asheville, NC 32

Hartford, CT 32 Flagstaff, AZ 32

Los Angeles, CA 38 Hilton Head, SC 34

Miami, FL 36 Fort Myers, FL 34

Pittsburgh, PA 32 Santa Fe, NM 31

A. compute the mean, variance, and standard deviation for the sample of cities and the sample of retirement areas.

B. What observations can be made based on the two samples?

25. Consider a sample with data values of 10, 20, 12, 17, and 16. Compute the z-score for each of the five observations.

57. A survey of subscribers to Fortune magazine asked the following question: " How many of the last four issues have you read?" Suppose that the following frequency distribution summarizes 500 responses.

Number Read Frequency

0 15

1 10

2 40

3 85

4 350

Total 500

A. What is the mean number of issues read by a Fortune Subscriber?

B. What is the standard deviation of the number of issues read?

#### Solution Summary

The solution gives the details of calculation of mean, standard deviation and z score.