calculate and explain the following

2) Assume the distribution of the number of people per household in the United States is shown in the following table:

x	P(x)
2	0.27
3	0.25
4	0.28
5	0.13
6	0.04
7	0.03

a) Calculate the expected number of people per household in the United States.

b) Compute the standard deviation of the number of people per household.

3) For a normally distributed population with=200and=20, determine the standardized z-value for each of the following:

a) x=225

b) x=190

c) x=240