Question

The percentage, P, of U.S. voters who use punch cards or lever machines in national elections can be modeled by the formula: P = −2.5x + 63.1 where x is the number of years after 1994. In which years will fewer than 38.1% of U.S. voters use punch cards or lever machines?

Answer 1

From 2004 onwards, fewer than 38.1% of U.S. voters use punch cards or lever machines

Explanation:

The percentage of U.S. voters who use punch cards or lever machines in national elections, in x years after 1994, is given by the following equation:

`P(x) = -2.5x + 63.1`

In which years will fewer than 38.1% of U.S. voters use punch cards or lever machines?

In x years after 1994 onwards.

x is found when P(x) = 38.1.

So

`P(x) = -2.5x + 63.1`

`38.1 = -2.5x + 63.1`

`2.5x = 25`

`x = (25)/(2.5)`

`x = 10`

From 2004 onwards, fewer than 38.1% of U.S. voters use punch cards or lever machines