4- Pabst Dental Supplies is evaluating the introduction of a new product. The possible levels of unit sales and the probabilities of occurrence are given. Possible market reaction Low response. Moderate response High response.. Very high response Sales in units 30 40 Probabilities .10 .20 .40 .30 75 80 a. What is the expected value of unit sales for the new product? b. What is the standard deviation of unit sales