The ratings of viewership for the three major networks during prime time recently were as follows. Also shown is the proportion of viewers watching each program.
|
Program
|
Network
|
Rating
|
Proportion
|
|
20/20
|
ABC
|
13.8
|
0.44
|
|
CSI
|
CBS
|
10.4
|
0.33
|
|
Law and Order
|
NBC
|
7.5
|
0.23
|
a. What is the mean rating given a program that evening?
b. How many standard deviations above or below the mean is the rating for each one of the programs?