Question

From a survey of 20 families in a society, the following data was
obtained
No. of children
0
1
2
3
4
No. of families
5
11
20
2
For the random variable X = number of children in a randomly
chosen family, Find E(X) and V(X).​

Answer 1

Step-by-step explanation:

v(x) =1.2275 is the answer to the solution

Answer 2

Answer:

$E(X)=\frac{23}{20}$  and  $V(X)=\frac{491}{400}$

Step-by-step explanation:

The probability distribution of $X$ is

Mean  $=$ ∑$p_ix_i=\frac{23}{20}$

Variance $(X),=$ ∑$p_ix_i^2-(mean)^2$

                      $=\frac{51}{20}-(\frac{23}{20} )^2 =\frac{1020-529}{400} =\frac{491}{400}$