## Question 925:

1## Answer:

No answer provided yet.We can use the weighted mean to generate a mean of all 3 classes. The question doesn't explicitly state to use the weighted mean but because we are given class sizes we can use that information to weight the averages. This way the larger class (35 students ) mean counts more than the smaller class (28) mean.The weighted mean is found by multiplying the class size by their mean and dividing that product by the sum of all the class sizes.

83(28)+80(32)+76(35) / 28+32+35 = 7544/95 = 79.41053.

Notice that this is slightly different than the arithmetic mean which would generate 79.667 and that is because the class with the lowest mean grade of 76 had the largest class.