Individuals filing the Zambia Revenue Authority income tax returns prior to March 31 had an average refund of K1056. Consider the population of last minute filers who mail their returns during the last 5 days of the income tax period (typically April 10 to April 15)

I. A researcher suggests that one of the reasons individuals wait until the last 5 days to file their returns is that on average those individuals have a lower refund than early filers. Develop an appropriate hypothesis such that rejection of H 0 will support the researchers contention

ii Using a = 0.05, what is the critical value for the test statistic?

iii. What is the rejection of rule at a=0.05?

iv. For a sample of 400 individuals who filed a return between April 10 and Aril 15, the sample mean refund was K910 and the sample standard deviation was K1600. Compute the value of the test statistic

v. What is your conclusion

vi. What is the p value for this test?