JEE Main 2021 — Statistics Question with Solution
From: JEE Main 2021 (Online) 20th July Morning Shift
Question
The mean of 6 distinct observations is 6.5 and their variance is 10.25. If 4 out of 6 observations are 2, 4, 5 and 7, then the remaining two observations are :
Choose an option
Show full solutionCorrect option: A
Correct answer
A10, 11
Step-by-step explanation
Let other two numbers be a, (21 a)
Now,
(Using formula for variance)
a = 10 and (21 a) = 21 10 = 11
So, remaining two observations are 10, 11.
Option (1) is correct.
Now,
(Using formula for variance)
a = 10 and (21 a) = 21 10 = 11
So, remaining two observations are 10, 11.
Option (1) is correct.
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Statistics chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.
Solve interactively →About this question
This is a previous-year question from JEE Main 2021, covering the Statistics chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.