Q1) In a random sample of 545 accountants engaged in preparing county operating budgets, 117 indicated that estimates f cash flow were the most difficult element of the budget to derive.

a) Test at the 5% level the null hypothesis that at least 25% of al accountants find cash flow estimates the most difficult to derive.

b) Based on the procedure used in part (a), what is the probability that the null hypothesis would be rejected if the true percentage of those finding cash flow estimates was 20%? 25%? 30%?

2) Random sample of 10 students contains following observations (in hours) for time spent studying in the week before exams:

28           57        42        35        61        39        55        46        49        38

a) Determine the sample mean and standard deviation.

b) Test at 5% significance level null hypothesis that population mean is 40 hours against alternative that it is higher.