If a discrete random variable X has the following probability distribution :
| X | $\frac{2}{3}$ | 1 | $\frac{4}{3}$ |
| P(X) | $c^2$ | $c^2$ | $c$ |
then c is :
Answer & explanation
Correct answer: option 1
From the table
$∑p_i=1⇒c^2+c^2+c=1$
so $2c^2+c-1=0$
$2c^2+2c-c-1=0⇒2c(c+1)-1(c+1)=0$
so $c=\frac{1}{2},-1$ (Not possible)
so $c=\frac{1}{2}$