Home
Class 12
MATHS
Mean of 5 observation is 7. if four of t...

Mean of 5 observation is 7. if four of these observation are 6,7,8,10 and one is missing, then te variance of all the five observations is

A

2

B

6

C

8

D

4

Text Solution

Verified by Experts

The correct Answer is:
D
`because7=(6+7+8+10+x_(5))/(5)impliesx_(5)=4`
`becausesigma=(sum(x_(i)-overline(x))^(2))/(5)=(1)/(5)[1+0+1+9+9]=4`
Promotional Banner

Similar Questions

Explore conceptually related problems

Mean of 5observations is 7. If four of these observations are 6,7,8,10 and one is missing then the variance of all the five observations is

The mean and variance of 7 observations are 8 and 16 respectively. If two observations are 6 and 8, then the variance of the remaining 5 observations is :

The mean and variance of the 7 observations is 8 and 12 resp. . If two observations are 8 and 6 . find the variance of the remaining observation

Suppose arithmetic mean of "10" observations is "10" and variance is "40." Further let arithmetic mean and variance of "6" observations from these "10 observations be "6" and "20" respectively.Then the variance of remaining observations is

The mean of the observation 7, 8, 9, 11 and 15 is 10.

If the mean of the observation x, x+3, x+5, x+7 and x+10 is 9, then mean of the last three observations is

The mean of 5 observations is 60, the mean of 10 observations is 30 and the mean of 15 observations is 20. The mean of all the 30 observations is (a)20quad (b) 25quad (c) 30 (d) 40