Question

The probability distribution of number of calls coming to a call center every 15 minute period is shown
below.

x 5 6 7 8 9 10 11 12 13

p ( x ) 0.02 0.04 0.07 0.08 0.09 0.11 0.12 0.13 0.10
Continued…
x 14 15 16 17 18 19 20

p ( x ) 0.07 0.06 0.04 0.03 0.02 0.01 0.01

1. This probability distribution is an example of a
(a) continuous probability distribution
(b) discrete probability distribution
(c) binomial distribution
(d) Poisson distribution
(e) None of the above
2. The probability of no more than 10 calls in a 15 minute interval:
(a) 0.55
(b) 0.60
(c) 0.30
(d) 0.35
(e) 0.41
3. The probability of getting at least 8 calls in a 15 minute interval:
(a) 0.85
(b) 0.79
(c) 0.13
(d) 0.87
(e) 0.89
4. The expected number of calls is:
(a) 12.24
(b) 13.51
(c) 11.34
(d) 0.54
(e) none of the above
5. The standard deviation of the calls are
(a) 1.54
(b) 1.45
(c) 4.35
(d) 3.25
(e) 2.36