An operation manager at an electronics company wants to test their amplifiers. The design engineer claims they have a mean output of 364 watts with a standard deviation of 12. What is the probability that the mean amplifier output would differ from the population mean by more than 0.9 watts in a sample of 52 amplifiers if the claim is true? Round your answer to four decimal places.

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?