1.An appliance repair shop may get up to 3 calls in an hour. The probability they get 3 calls is 0.15, the probability of 2 calls is 0.43, and the probability of 1 call is 0.31

a)What is the probability they get 0 calls in an hour?

b)Construct the probability distribution for the number of calls.

c). What is the mean number of calls the shop receives in an hour?

c)What is the standard deviation of the number of calls?