Hi can you help me with this question? I am really having a hard time with this.

Sampson Corp. is evaluating the introduction of a new product. The possible |evels of unit sales and the probabilities of their occurrence are shown next: Possible Sales Market Reaction in Unite Probebililiee Low rmponae 2t} .40 Moderate response 70 .20 High response 80 .10 Very high response 100 .30 a. What is the expected value of unit sales fortl'e new product? (Do not round Intermediate calculations and round your answer to the nearest whole unit.) Expected value unite b. What is the standard deviation of unit sales? {Do not round Inten'nedl ate calculations. Round your answer to 2 decimal places.) Standard deviation unite