Individuals filing federal income tax returns prior to March 31 received an average refund of $1056. Consider the population of "last minute" filers who mail their tax return during the last five days of the income tax period. A researcher suggests that a reason these individuals wait until the last five days in that on average these individuals receive lower refunds than do early filers. For a sample of 400 individuals who filed a tax return "last minute", the sample mean refund was $910. Based on prior experience, a population standard deviation of $1,600 may be assumed. What is the hypothesis test to test the researchers claim using = 0.01.