Maryanne owns a mediumsized shop The probability model below

Maryanne owns a medium-sized shop. The probability model below describes the number of customers that may come in the store sick on any given day. What is the mean number of customers coming in sick each day?

XNumber of Sick Cust. P(X)

0 0.05

1 0.40

2 0.30

3 0.20

4 0.05

Solution

Consider the table:      
      
x   P(x)   x P(x)
0   0.05   0
1   0.4   0.4
2   0.3   0.6
3   0.2   0.6
4   0.05   0.2
      
Total       1.8

Thus,

mean = Sum( x P(x)) = 1.8 [ANSWER]