Question

the following is a probability distribution of the number of people placed on hold when they call a radio talk show

d) Are A and B indepenident 0.lo O.Ilos 4、 The following is a probability distribution of the number of people placed on hold when they call a radio talk show. O. O.log -44 4 0.36 0.31 0.23 a) Find the probability that at least 2 people are placed on hold. b) Calculate the mean (expected value) of the distribution. ニ11.llo

Answer 1

a)

The probability that at least 2 people are placed on hold is

P(X > 2)-PlX-2)+P(X-3) + PlX = 4) 0.31+0.23+0.36 = 0.9

b)

Following table shows the calculations:

X	P(X)	xP(x)	x^2*P(x)
1	0.1	0.1	0.1
2	0.31	0.62	1.24
3	0.23	0.69	2.07
4	0.36	1.44	5.76
Total		2.85	9.17

So expected value is

E(x)-PX-x)- 2.85

(c)

The standard deviation is

P(X-)V9.17-2.8521.0235