Question

The percent P of the U.S. population with Internet access is given by

25P − 34t = 1378
where t is the number of years past 1990.

(a) What percent of the U.S. population had Internet access in 2001? (Round your answer to one decimal place.)
P = %


(b) In what year will 93% have Internet access?

Answer 1

(a) To find the percent of the U.S. population with Internet access in 2001, we substitute t=11 (2001 - 1990) into the equation:

25P - 34 * 11 = 1378

Solving for P:

25P = 1378 + 34 * 11

25P = 1378 + 374

25P = 1752

P = 70.08

So, 70.1% of the U.S. population had Internet access in 2001.

(b) To find the year when 93% of the U.S. population will have Internet access, we substitute P = 93 and solve for t:

25P - 34t = 1378

25 * 93 - 34t = 1378

2325 - 34t = 1378

34t = 2325 - 1378

34t = 947

t = 947 / 34

t = 27.79

So, approximately 27.8 years after 1990, or around the year 2018, 93% of the U.S. population is expected to have Internet access.