According to an IRS study, it takes a mean time of 330 minutes for taxpayers to prepare, copy and electronically transfer a 1040 tax form. The standard deviation of this distribution is 80 minutes. A consumer watchdog agency selects a random sample of 40 taxpayers for further study.
A. What is the shape, mean(expected value), and standard deviation of the sampling distribution of the sample mean for samples of size 40?
B. What is the probability that the sample mean is greater than 350 minutes?