In an experiment involving high-temperature performance of two types of transistors, a sample of 60 transistors of type a were tested and were found to have a mean lifetime of 1437 hours and a standard deviation of 179 hours. a sample of 180 transistors of type b were tested and were found to have a mean lifetime of 1356 hours and a standard deviation of 244 hours.
1. can you conclude that the mean lifetimes differ between the two types of transistors?