Question

In 1980, the average cost of a pack of cigarettes was $0.88. In 2000, the average cost was $5.31 per pack.

What is the average rate of change of the cost of a pack of cigarettes? What is another name for the average rate of change?

Round your answer to the nearest cent.

Answer 1

The average rate of change of the cost of a pack is 22 cents per year.

Another name for the average rate of change is slope.

Explanation:

The average rate of change of the cost of a pack (
`r`), in monetary units per year, is equal to the change in the average cost of a pack (
`\Delta c`), in monetary units, divided by the change in time (
`\Delta t`), in years. Then, the average rate of change is:

`r = (\$\,5.31-\$\,0.88)/(2000-1980)`

`r = \$\,0.22\,(1)/(yr)`

The average rate of change of the cost of a pack is 22 cents per year.

Another name for the average rate of change is slope.