Recall from Exercise 4.13 (page 170) that each month a brokerage house studies various companies and rates each company's stock as being either "low risk" or "moderate to high risk." In a recent report, the brokerage house summarized its findings about 15 aerospace companies and 25 food retailers in the following table:

If we randomly select one of the total of 40 companies, find
a. The probability that the company's stock is moderate to high risk given that the firm is an aerospace company.
b. The probability that the company's stock is moderate to high risk given that the firm is a food retailer.
c. Determine if the events type is independent of the level of risk of the firm's stock.

Low Risk Moderate to High Risk Company Type Aerospace company Food retailer 15 10