Question

if the combined mean of the two group is 40/3 and if the mean
of one group is with 10 observations is 15,then the mean of the other
group with 8 observations is​

Answer 1

Answer: 11.25

Step-by-step explanation:

We know that Mean = Sum of observations/No. of observations,

thus Sum of observations = Mean*No. of observations

Combined mean of two groups = 40/3

no. of observations in group 1 = 10

no. of observations in group 2 = 8

therefore, total no. of observations = 10+8 = 18

therefore, sum of all observations in the two groups = 18*(40/3) = 240

Mean of 1 group=15

Thus, the sum of all observations of the first group= 15*10=150

Let mean of the second group be x

Thus, the sum of all observations of the second group= x*8 = 8x

So, sum of observations of group1 and group2 = sum of all observations

or, 150+8x=240

or, 8x=240-150=90

therefore the mean of second group=x=90/8=11.25

Hope it helps.