JEE Main 2022 · 30 Jul · Shift 2 · Mathematics Q89

MathematicsInteger+4 / -1Question 89 of 90

The probability distribution of a random variable X is $P(X=i)=\dfrac1{2^i}$ , i = 1, 2, 3, ........ The variance of X is equal to _______.

Your answer

Answer and worked solution

Official answer: 2

Geometric distribution with $p=\frac12$ : $\operatorname{Var}=\frac{q}{p^2}=\frac{1/2}{1/4}=2$ .

Answer: 2

JEE Main 2022 · 30 Jul · Shift 2, Mathematics question 89