Hi Jes,

I hope it's not too late to answer your question.

All the information you need is given in the problem. Consider the following (not correct) way of finding the average salary:

"So the MBA's get 42K and the BA's get 28K. That means the average is 42+28/2 = 70/2 = 35K" [Again, this is wrong]

You have more information than this, namely:

Total Employees: 25

8 MBA's @ 42.5K on average

17 BA's @ 28K on average

Using this information, think about the company's *entire* payroll (in dollars) divided by its total number of employees. This will give you the mean salary for the average joe (regardless of degree).

Again:

mean salary = total payroll/number of employees

Actually, to build on your understanding of weights in calculating GPA, consider this formula for calculating a GPA:

Average GPA = (Grade1 * Units1) + (Grade2 * Units2) + ... + (GradeN * UnitsN) / Total Units

So if I have these grades and my classes vary between 3 and 4 units:

GPA = (4.0 * 4) + (3.0 * 3) + (3.5 * 4)/11 = 39/11 = 3.54

Hope you see the analogy with the business example