300 80
40
48
7
12
15
m
10:30 = 100:
4:5 - 40 :
20:10 2:
300
U
L
A
3:5 - 6:
2:3 = 10:
2:6 1:
T
E
R
3:49:
12:15 = 4:
300 : 800 = 30:
S
С
I
99 : 77= 9:
1:5= 5:
4:12 = 16:
H
F
4:44 = 1:
6:12= 20 :
15:30 = 1:
N
D
111

Aparticular telephone number is used to receive both voice calls and fax messages. suppose that 25% of the incoming calls involve fax messages, and consider a sample of 25 incoming calls. (a) what is the expected number of calls among the 25 that involve a fax message?