For the past 65 years, the mean high temperature in Sacramento on May 15thwas 78.4 F with a standard deviation ofs= 8.1 F. Compute the interval that is within one standard deviation of the sample mean. Give the the lower endpoint of your interval as your answer.

A company manufactures tennis balls. A sample of 25 balls are dropped onto a concrete surface from a height of 100 inches. The mean bounce height is 55.1 inches with a standard deviation of 4.3 inches. Compute the interval that is within two standard deviations of the sample mean. Give the the lower endpoint of your interval as your answer.