JEE Main 2020MathematicsStatisticsCalculation Of Standard Deviation Variance And Mean Deviation Of Grouped And Ungrouped DatamediumNumerical

JEE Main 2020 — Statistics Question with Solution

From: JEE Main 2020 (Online) 4th September Evening Slot

Question

If the variance of the following frequency distribution :

Class         : 10–20 20–30 30–40

Frequency :    2          x          2

is 50, then x is equal to____

Enter your answer

Show full solutionCorrect answer: 4
Correct answer
4

Step-by-step explanation

xi = midpoint of class interval
JEE Main 2020 (Online) 4th September Evening Slot Mathematics - Statistics Question 83 English Explanation

Variance(

Also,

= = 25

Given, Variance = 50

50 =

x = 4

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 2020, 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.