Question

If the mean of 25 observations is 27 and each observation is decreased by 7, what will be the new mean ?

Class 10

❎ Don't Spamming ❎

Answer 1

Mean = sum of observation/no. of observations
27 = x/25
x = 675

If we reduce each observation by 7, we are reducing total of 25×7 from the sum.

new mean = 675-175/25
= 500/25
= 20.

Mark as brainliest,if it helped.

Answer 2

Given that the mean of 25 observations is 27.

Then,

Sum of 25 numbers = 25 * Mean of 25 observations = 25 * 27 = 675.

---------------------------------------------------------------------------------------------------------------

Given that each observation is decreased by 7.

Then, sum of 25 observations = 675 - (25 * 7)

= > 675 - 175

= > 500.

----------------------------------------------------------------------------------------------------------------

Hence,

Mean of 25 observations = 500/25

= > 20.

-------------------------------------------------------------------------------------------------------------

Therefore, the new mean = 20.

Hope this helps!