The average price of a gallon of unleaded regular gasoline was reported to be $3.90 in southwest Florida. 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 36 service stations is within $.05 of the population mean?
b) What is the probability that the mean price for a sample of 64 service stations is within $.05 of the population mean?
c) What is the probability that the mean price for a sample of 100 service stations is within $.05 of the population mean?