Question

the mean of 10 observations is 20 and that of another 15 observations is 16. find the mean of all the 25 observations

Answer 1

Heya,

Here is required solution:-

Mean = Sum of the observations / No. of observations.

20 = Sum of the observations/10

Sum of the observations = 200

16 = Sum of the observations / 15

Sum of the observations = 240

Total sum of the observations = 440

Total no. of observations = 25

New mean = 440/25

= 17.6

Hope it helps u............

Answer 2

Hey !!

Mean = Sum of the observations / No. of observations.

Mean = 20
No. of observations = 10


Sum of the observations = Mean x No. of observations = 20 x 10 = 200

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Mean = 16

No. of observations = 15

Sum of the observations = 16 x 15 = 240

Total sum of the observations = 200 + 240 = 440

Total no. of observations = 15 + 10 = 25

New mean = 440/25

= 17.6