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 after 1990. what percent of the u.s. population had interent access in 2005? (round to one decimal place) in what year will 89% have internent access?

Answer 1

Answer:

• Hence, 75.52 percent of the u.s. population had internet access in 2005.
• After 25 years or in the year 2015 89% have internet access.

Step-by-step explanation:

the percent p of the u.s. population with internet access is given by:

25 p-34 t=1378

where t is the number of years after 1990.

• We are asked to find  what percent of the u.s. population had internet access in 2005 i.e. we need to find the value of p after 15 years i.e. t=15.

⇒  25p-34×(15)=1378

⇒  25p-510=1378

⇒  25p=1378+510

⇒  25p=1888

⇒  p=75.52

Hence, 75.52 percent of the u.s. population had internet access in 2005.

• Next we are asked to find in what year will 89% have internet access?

i.e. we have to find the value of t when we are given p=89

⇒  25×89-34t=1378

⇒  2225-34t=1378

⇒  2225-1378=34t

⇒  847=34t

⇒  or 34t=847

⇒  t=24.9112≈25

Hence after 25 years 89% will have internet access.

i.e. in the year 2015 89% will have internet access.