1. In how many di?erent ways can 6 quali?ed individuals be assigned to
(a) Three trainee positions available if the positions are identical?
(b) Three trainee positions eventually if the positions di?er?
(c) Six trainee positions available if the positions di?er?
2. The probability distribution of lunch customers at a restaurant is given in Table 3.5. Calculate
(a) the expected number of lunch customers,
(b) the variance, and
(c) the standard deviation.
Table 3.5 Probability Distribution of Lunch Customers at a Restaurant
|
Number of Customers, X
|
Probability, PðXÞ
|
|
100
|
0.2
|
|
110
|
0.3
|
|
118
|
0.2
|
|
120
|
0.2
|
|
125
|
0.1
|
|
1.0
|