The mean number of heads in two tosses of a coin is :

2 $\frac{1}{2}$ 1 $\frac{3}{2}$

1

In two tosses of a coin No. of heads = 0, 1, 2 X = 0 1 2  P(x) =   ${}^{2}C_{0}\frac{1}{2^{2}}$  ${}^{2}C_{1}\frac{1}{2^{2}}$  ${}^{2}C_{2}\frac{1}{2^{2}}$  So mean = $\sum x_i P\left(x_i\right)$ $=0 \times{ }^2 C_0 \times \frac{1}{2^2}+2 C_1 \times \frac{1}{2^2}+2 \times{ }^2 C_2 \times \frac{1}{2^2}$ $=\frac{2}{4}+\frac{2}{4}=1$