Stats Questions (2) Needs all details to be shown

Pg 308   6.8 problem

The mean and standard deviation of a random sample of n measurements are equal to 33.9 and 3.3 respectively.

a.      Find a 95% confidence interval for u if n = 100.

b.      Find a 95% confidence interval for u if n = 400.

c.      Find the widths of the confidence intervals found in parts a and b. What is the effect on the width of a confidence interval of quadrupling the sample size while holding the confidence coefficient fixed?

Pg 325       6.47 problem

Is Starbucks coffee overpriced? The Minneapolis Star Tribune (August 12, 2008) reported that 73% of Americans say that Starbucks coffee is overpriced. The source of this information was a national telephone survey of this information was a national telephone survey of 1,000 American adults conducted by Rasmussen Reports.

a.      Identify the population of interest in this study.

b.      Identify the sample for the study.

c.      Identify the parameter of interest in the study.

d.      Find and interpret a 95% confidence interval for the parameter of interest.