JEE Main 2018 — Statistics Question with Solution
From: JEE Main 2018 (Online) 16th April Morning Slot
Question
The mean and the standard deviation(s.d.) of five observations are9 and 0, respectively. If one of the observations is changed such that the mean of the new set of five observations becomes 10, then their s.d. is :
Choose an option
Show full solutionCorrect option: C
Correct answer
C2
Step-by-step explanation
Here mean = = 9
= = 9
= 9 5 = 45
Now, standard deviation = 0
all the five terms are same i.e.; 9
Now for changed observation
=
x5 = 14
new =
= = 2
= = 9
= 9 5 = 45
Now, standard deviation = 0
all the five terms are same i.e.; 9
Now for changed observation
=
x5 = 14
new =
= = 2
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