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

JEE Main 2020Statistics Question with Solution

From: JEE Main 2020 (Online) 9th January Morning Slot

Question

Let the observations xi (1 i 10) satisfy the
equations, = 10 and = 40.
If and are the mean and the variance of the
observations, x1 – 3, x2 – 3, ...., x10 – 3, then
the ordered pair (, ) is equal to :

Choose an option

Show full solutionCorrect option: B
Correct answer
B(3, 3)

Step-by-step explanation

= 10

x1 + x2 + .... + x10 = 60 ....(1)

= 40

() + 25 10 -
10( x1 + x2 + .... + x10) = 40

= 390 .....(2)

From question,
=

= = 3

And = variance = - 2

= - 9

= - 9

= 12 - 9 = 3

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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.