According to an irs study, it takes a mean of 330 minutes for taxpayers to prepare, copy, and electronically file a 1040 tax form. this distribution of times follows the normal distribution and the standard deviation is 80 minutes. a consumer watchdog agency selects a random sample of 40 taxpayers. a. what is the standard error of the mean in this example? b. what is the likelihood the sample mean is greater than 360 minutes?