Question

If, in a set of 30 observations, each value is increased by 10, the arithmetic mean increases by___.
​

Answer 1

Step-by-step explanation:

The mean of 20 observation is 25

∴ Sum of 20 observations =20×25=500

⇒ New sum of 20 observations after increasing each observation by 2 =(2×20)+500=40+500=540

⇒ Required mean =

20

540

=27