Question

If the mean of 10 observations is 7 and the mean of 15 observations is 12. Then find the mean of all the observations is​

Answer 1

Answer:

The mean of all observations is 10

Step-by-step explanation:

Let the sum of first 10 observations be x

then x/10 = 7

x = 70

Let the sum of 15 observations be y

then y/15=12

y = 180

mean of all observations=( 70+180)/(10+15)

= 250/25 = 10