WB JEE 2021 | Statistics Question 1 | Mathematics

WB JEE 2021

MCQ (Single Correct Answer)

-0.25

The mean and variance of a binomial distribution are 4 and 2 respectively. Then the probability of exactly two successes is

$${7 \over {64}}$$

$${{21} \over {128}}$$

$${7 \over {32}}$$

$${9 \over {32}}$$

WB JEE 2017

MCQ (Single Correct Answer)

-0.25

Mean of n observations x₁, x₂, ...., x_n is $$\overline x $$. If an observation x_q is replaced by x_q' then the new mean is

$$\overline x - {x_q} + {x_9}'$$

$${{(n - 1)\overline x + {x_q}'} \over n}$$

$${{(n - 1)\overline x - {x_q}'} \over n}$$

$${{n\overline x - {x_q} + {x_q}'} \over n}$$

WB JEE Subjects