Q89 of 108 Page 271

For the following probability distribution


E(X2) is equal to

Given, Probability distribution table is given,

Now,







Hence, E(X2) =10

More from this chapter

All 108 →
87

The probability distribution of a discrete random variable X is given below:



The value of k is

 88

For the following probability distribution:


E(X) is equal to :

 90

Suppose a random variable X follows the binomial distribution with parameters n and p, where 0 < p < 1. If P(x = r) / P(x = n–r) is independent of n and r, then p equals

 91

In a college, 30% students fail in physics, 25% fail in mathematics and 10% fail in both. One student is chosen at random. The probability that she fails in physics if she has failed in mathematics is