On January 4, 1970 the price of a widget was $21.30. On January 4, 1981 the price of a widget was $91.41. Find the average rate of change in the price of a widget from 1970 to 1981. Round to the nearest cent.

The average rate of change is $LaTeX: \displaystyle \frac{91.41-21.30}{1981-1970}= 6.37$ dollars per year.