In 1992, a software company had a profit of 3,000,000. In 1998, the company had a profit of 21,000,000. Find the average rate of change of the company's profit per year.

Profit then 30M. Profit later, 210M.

Change in profit is obviously 180M, right?

OK, so that change is over how many years? 1992 to 1998 - 6 years.

Profit changed by 180,000,000 over 6 years, so on average it changed $180,000,000 / 6 per year.