The sum of 100 observations and the sum of their squares are 400 and 2475, respectively. Later on, three observations, 3, 4 and 5, were found to be incorrect. If the incorrect observations are omitted, then the variance of the remaining observations is :
← JEE Main 2017 · 9 Apr · Shift 1
MathematicsSingle correct+4 / -1Question 87 of 90
JEE Main 2017 · 9 Apr · Shift 1, Mathematics question 87
Answer and worked solution
Official answer: D
97 observations remain with sum 388 and sum of squares 2425. The mean is 4, so the variance is .