Question

if a mean of 10 observation be 20 and mean of 15 other observation be 16 then find the mean of all 25 observation
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Answer 1

Answer:

mean of 10 observations=20

sum of 10 observations=10×20=200

mean of 15 observations=16

sum of 15 observations=15×16=240

total sum=200+240=440

mean of 25 observations=440/25=17.6