Business Statistics: A Decision-Making Approach (Eight Edition) by David F. Groebner & Patrick W. Shannon & Kent D. Smith & Phillip C. Fry

Author:David F. Groebner & Patrick W. Shannon & Kent D. Smith & Phillip C. Fry [Groebner, David F. & Shannon, Patrick W. & Smith, Kent D. & Fry, Phillip C.]
Language: eng
Format: epub
ISBN: 9780130934918
Amazon: 013179633X
Publisher: Prentice Hall
Published: 2001-01-07T17:00:00+00:00

a. Calculate the sample standard deviation and mean speed produced by cues in the two weight categories: (1) under 19 ounces and (2) at or above 19 ounces.

b. Calculate a 95% confidence interval for the difference in the average speed of a cue ball generated by each of the weight categories.

c. Is the anecdotal evidence correct? Support your assertion.

d. What assumptions are required so that your results in part b would be valid?

10-17. The Federal Reserve reported in its comprehensive Survey of Consumer Finances, released every three years, that the average income of families in the United States declined from 2001 to 2004. This was the first decline since 1989–1992. A sample of incomes was taken in 2001 and repeated in 2004. After adjusting for inflation, the data that arise from these samples are given in a file entitled Incomes.