Find the mean of 7 numbers if the mean of the first 4 numbers is 5 and the mean of the last 3 numbers is 12. What is the mean of the combined data sets?

8

Step-by-step explanation:

Consider that the way to calculate the mean is the sum total of the values in the series, divided by the number of the series so Mean = SumX / N

We need to calculate the value of the first four numbers and last 3 numbers.

For the first set

5 = X/4 Therefore 5*4 = X so X is 20

For the second set

12 = Y/3 therefore 12*3 = Y so Y is 36

Add them together to get the sum of the full set (remember the calculation for the mean)

36 + 20 = 56

Mean = Sum X (which is 56) / N (which is 7)

So the answer is 56/7 = 8