1.The following probability distribution table is for the random variable, , the number of children under the age of 20 years in households of a small town.Remember to show all work to answer the following questions.

x

P(x)

0

0.17

1

0.40

2

0.25

3

0.11

4

0.07

> 4

0.00

a)Determine the mean of x .

b)Determine the standard deviation of x.

c)Find the probability of a household consisting of 3 or more children under the age of 20.