Question

mean of 20 observation is 17 if the observation , observation is 40 replaced by 12 find its new mean.

Answer 1

mean = m=17
no of observations=n=20

new mean =(m*n +12-40)/n
=(17*20+12-40)/20
=(340+12-40)/20
=312/20
=156/10
=15.6
therefore
new mean =15.6

Answer 2

Answer:

$\huge\bold\green{Required \: answer}$

⇨★

Solution:

Since mean of 20 observations is 17

∴ Sum of the 20 observations = 17 × 20 = 340

New sum of 20 observations = 340 – 40 + 12 = 312

New mean = 312/20= 15.6

⇨★ 15.6

$\huge\boxed{\fcolorbox{blue}{orange}{hope it helps}}$