Question

A sample of 12 measurements has a mean of 8.5 and a sample of 20 measurements has a mean of 7.5. Find the mean of all 32 measurements.

Answer 1

multiply 8.5 by 12, multiply 7.5 by 20, add them together to get 252, then divide that by 32 to get 7.875. 7.875 is the mean of all 32 measurements