The mean and standard deviation of 6 observations are 8 and 4 respectively. If each observation is multiplied by 3, find the new mean and new standard deviation of the resulting observations.
Given, The mean is 8 and SD is 4 for 6 observation
To Find: Find a new mean and new standard Deviation.
Formula Used: Standard Deviation ()
Explanation:
Let Assume, x1,x2,x3,…,x6 be the given observations.
So, Variance (X) = 8 (Given)
n=6
and (SD)
X =
Now, Let u1,u2,…u20 be the new observation,
When we multiply the new observation by 3, then
Ui=3xi (for i=1,2,3…,6) ……(i)
Now,
3×8 = 25
U = 24
Therefore, The Mean of new observation is 24
Now,
Standard Deviation
Since, Variance (X) =16
Variance (U) =
9×16
Hence, The mean of new observation is 24 and Standard deviation of new data is 12.