1) A researcher wishes to estimate the number of days it takes an automobile dealer to sell a car. A sample of 50 cars had a mean time on the dealer ' s lot of 54 days. Assume the population standard deviation to be 6 days. Find the best point estimate of the population mean and the 95% confidence interval of the population mean.

2) A researcher wishes to test the claim that the average cost of tuition and fees at a four-year public college is greater than $5700. She selects a random sample of 36 four-year publish colleges and finds the mean to be $5950. The population standard deviation is $659. Is there evidence to support the claim at a = .05?

3) A researcher claims that the average wind speed in a certain city is 8 miles per hour. A sample of 32 days has an average wind speed of 8.2 miles per hour. The standard deviation of the population is .6 miles per hour. At a= .05, is there enough evidence to reject the claim?