1. An auditor is interested in the mean value of a company's accounts receivable. He randomly samples 200 accounts receivable and finds that the mean accounts receivable is $231. From past experience, he knows that the standard deviation is $25. Use a 0.01 level of significance to test whether the population mean accounts receivable is different from $200.

2. An investment advisor is interested in determining whether a retirement community represents a potential clientele base. Of the 2,000 residents, he randomly samples 100 individuals and finds their mean wealth to be $525,000 with a sample standard deviation of $52,000. Use a 0.10 level of significance to test the hypothesis that the mean wealth is greater than $500,000.