Please explain in great detail how you got the answer I am t

*Please explain in great detail how you got the answer. I am trying to understand the materials. Thank you in advance.*

The probability distribution of the daily demand for a product is shown below.

Demand Probability

0 0.05

1 0.10

2 0.15

3 0.35

4 0.20

5 0.10

6 0.05

a. What is the expected number of units demanded per day?

b. Determine the variance and the standard deviation.

Solution