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 25 .20 Moderate response 30 .10 High response 50 .10 Very high response 70 .60 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?