JEE Main 2021 — Statistics Question with Solution
From: JEE Main 2021 (Online) 27th July Morning Shift
Question
If the mean and variance of the following data : 6, 10, 7, 13, a, 12, b, 12 are 9 and
respectively, then (a b)2 is equal to :
respectively, then (a b)2 is equal to :
Choose an option
Show full solutionCorrect option: D
Correct answer
D16
Step-by-step explanation
Mean =
60 + a + b = 72
a + b = 12 .....(1)
variance
a2 + b2 + 2ab = 144
80 + 2ab = 144
2ab = 64
60 + a + b = 72
a + b = 12 .....(1)
variance
a2 + b2 + 2ab = 144
80 + 2ab = 144
2ab = 64
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