Maher Saddles, Inc., produces bicycle seats. Maher’s operations manager has recently made a change in the production process for the company’s high-end seat.

After waiting for the process to become stable, he took a random sample of 25 assembly times and found a standard deviation of 47 seconds. He recognizes this is only a point estimate of the variation in completion times and so wants to report both a 90% and a 95%

confidence interval estimate for the population variance.