Question

the mean of 8 observations is 40 if 5 is added to each observation then find the new mean

Answer 1

We know that Mean=Sum of terms/number of terms
As given
Mean=40 and number of terms=8 so
40=Sum of terms/8
Sum of terms=40*8=320 now by increasing each term by 5 sum of terms will increase by 8*5=40 so new Sum will be
Sum of terms=320+40=360
Again solving to find mean
Mean=Sum of terms/number of terms
Mean=360/8=45
Please mark as brainliest.

Answer 2

Formula to be used:
(i) $\text{ Mean}= \frac{\text{ sum of the values} }{\text{Number of observations}}$
(ii)$\text{ Total} = \text{ Mean} \times\text{ Number of observations}$
-----------------------------------------------------------------
Given, the mean of 8 observations is 40.

Number of observations=8
Mean=40

We know that ,
Total =  Mean × Number of observations
Total = 40×8=320

If 5 is added to each of the 8 observations, then the sum of the values will increase by  (5×8)=40.

New total = 320 + 40=360

$\text{ New Mean}= \frac{\text{ New Total} }{\text{Number of observations}}=\frac{360 }{8}=45$

Answer : New mean = 45