The average price of a gallon of unleaded gasoline was reported to be $3.13 in Illinois. Use this price as the population mean and assume the population standard deviation is $.20.
a. What is the probability that the mean price for a sample of 30 service stations is within $.03 of the population mean?
b.What is the probability that the mean price for a sample of 50 service stations is within $.03 of the population mean?
c.What is the probability that the mean price for a sample of 100 service stations is within $.03 of the population mean?
d.Which if any of the sample sizes (30), (50), and (100) would you recommend to have at least a .95 probabilty that the sample mean is within $.03 of the population mean?