Myers Business Systems is evaluating the introduction of a new product. The possible levels of unit sales and the probabilities of their occurrence are given next: Possible Market Reaction Sales in Units Probabilities Low response 15 .20 Moderate response 30 .30 High response 55 .20 Very high response 60 .30 a. What is the expected value of unit sales for the new product? (Do not round intermediate calculations and round your answer to the nearest whole unit.) b. What is the standard deviation of unit sales? (Do not round intermediate calculations. Round your answer to 2 decimal places.)