A sporting goods store sells softball bats. Let X be the numbers of bats sold on a typical day at the store. Based on the store historical data, the probability distribution of X is provided in the table below.

Sales (in units)

x	0	1	2	3
P()	0.19	0.374	0.335	0.101

3. What is the expected number of bats sold on a typical day?

4. Calculate the variance of the probability distribution.

5. What is the standard deviation of the probability distribution?

6. What is probability of observing the sale of no more than 1 bat at this sporting goods store?

7. What is the probability of observing the sale of at least one bat on a given day at this sporting goods store?

8. What is the probability of observing the sale of no more than two bats on a given day at this sporting goods store?

9. What is the probability of observing the sale of at least two bats on a given day at this sporting goods store?