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	Sales in Units			Probabilities
Low response		20			0.30
Moderate response		35			0.20
High response		50			0.20
Very high response		90			0.30

a. What is the expected value of unit sales for the new product?

Expected value

b. What is the standard deviation of unit sales? (Round the final answer to 2 decimal places.)

Standard deviation