Efficiency experts study the processes used to manufacture items in order to make them as efficient as possible. One of the steps used to manufacture a metal clamp
involves the drilling of three holes. In a sample of 81 clamps, the mean time to
complete this step was 42.8 seconds. Assume that the population standard deviation
is 8 seconds. What is the lower bound of the 98% confidence interval?
Round your answer to one decimal place (for example: 41.9).