1) A study of 35 golfers showed that their average score was 92. The standard deviation of the sample was 5.
a) Find the best point estimate of the mean.
b) Find the 95% confidence interval of the mean score for all golfers.
c) Find the 95% confidence interval of the mean score if the sample of 60 golfers is used.
d) Which interval is smaller? Explain why.
2) Pizza Hut wishes to find the 90% confidence interval of the true mean cost of a medium "veggie" pizza. How large a sample is needed if the store manager wants to be accurate to within $0.10? A previous study gave a standard deviation of $0.57.
3) A sample of 17 states has the cigarette taxes (in cents) listed:
112 120 98 55 71 35 99 124 62
150 150 55 100 132 20 70 93
Find the 98% confidence interval for this tax in all 50 states, the District of Columbia, and Puerto Rico.