# A sample of six college wrestlers had an average weight of 276 pounds

1. A study of 35 golfers showed that their average score on a particular course was 92. The standard deviation of the population is 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 a sample of 60 golfers is used instead of a sample of 35.

D. Which interval is smaller? Explain why.

2.A pizza shop owner wishes to find the 95% confidence interval of the true mean cost of a large plain pizza. How large should the sample be if she wishes to be accurate to within \$0.5? A previous study showed that the standard deviation of the price was \$0.26

3.A sample of six college wrestlers had an average weight of 276 pounds with a sample standard deviation of 12 pounds.

A..Find the 90% confidence interval of the true mean weight of all college wrestlers.

B..If a coach claimed that the average weight of wrestlers on the team is 310, would the claim be believable?

4.It has been reported that 20.4% of incoming freshmen indicate that they will major in business or a related field. A random sample of 400 incoming college freshmen was asked their preference, and 95 replied that they were considering business as a major.

A..Estimate the true proportion of freshman business majors with 98% confidence.

B..Does your interval contain 20.4?

5.Nearly one half of Americans aged 25 to 29 are unmarried. How large a sample is necessary to estimate the true proportion of unmarried Americans in this age group within 21/2 percentage points within 90% confidence?