In problem 77 on page 120, we have to determine, whether the typical levels and variances of salaries and bonuses of 350 CEO’s depend on the industry they serve.

For a quick look, let’s make a graph showing the averages and medians of the salaries and bonuses. The data are in thousands of dollars.

The graph shows very well, that CEO’s of financial companies get bonuses of a much higher level, because both the average and the median are much higher. If only the average was high, that could be attributed to a few outlieing values.

A graph of the variance of salaries and bonuses tells us, that salaries tend to be similar within company types. It is different with bonuses. Within some company types, namely the financial, cyclical, and the technology companies, bonuses can be quite different.

Details are show in the table below.