Statistics · JEE Advanced previous year questions

2024 1 question

1. Q132024 · 26 May 2024 · Paper 1· Numerical answer

   Let $X$ be a random variable, and let $P(X=x)$ denote the probability that $X$ takes the value $x$. Suppose that the points $(x,P(X=x))$, $x=0,1,2,3,4$, lie on a fixed straight line in the $xy$-plane, and $P(X=x)=0$ for all $x\in \mathbb{R}-\{0,1,2,3,4\}$. If the mean of $X$ is $\frac{5}{2}$, and the variance of $X$ is $\alpha$, then the value of $24\alpha$ is _____.

   Show answer

   Answer: 42