In the random sample of 545 accountants engaged in making county operating budgets, 117 indicated that estimates f cash flow were the most complex element of budget to derive.
a. Test at the 5% level the null hypothesis that at least 25% of al accountants find out cash flow estimates the most difficult to derive.
b. Based upon the procedure used in part (a), find out the probability that the null hypothesis would be rejected if the true percentage of those finding cash flow estimates was 20%? 25%? 30%?