JEE Main 2021 — Statistics Question with Solution
From: JEE Main 2021 (Online) 26th August Morning Shift
Question
The mean and standard deviation of 20 observations were calculated as 10 and 2.5 respectively. It was found that by mistake one data value was taken as 25 instead of 35. if and are the mean and standard deviation respectively for correct data, then (, ) is :
Choose an option
Show full solutionCorrect option: D
Correct answer
D(10.5, 26)
Step-by-step explanation
Given :
Mean
or xi = 200 (incorrect)
or 200 25 + 35 = 210 = xi (Correct)
Now correct
again given S.D = 2.5 ()
or (incorrect)
or
= 2725 (correct)
correct
= 26
or = 26
= 10.5, = 26
Mean
or xi = 200 (incorrect)
or 200 25 + 35 = 210 = xi (Correct)
Now correct
again given S.D = 2.5 ()
or (incorrect)
or
= 2725 (correct)
correct
= 26
or = 26
= 10.5, = 26
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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.