The average monthly bill for telephone subscribers from 1985 to 2008 can be modeled by B(x)= -1.857x+96.788 , where x is the number of years after 1980. If this model remains valid, in what year will the average monthly bill be $24.37?

The average monthly wireless phone bill would be $24.37 in the year _____?

(Do not round until the final answer. Then round to the nearest whole number as needed.)

The average monthly wireless phone bill would be $24.37 in the year 2019. 

Step-by-step explanation

The average monthly bill for telephone subscribers from 1985 to 2008 can be modeled by 

B(x)= -1.857x+96.788 

where x is the number of years after 1980

Given : 

Average monthly income = $24.37 

=> B(x) = 24.37 

- 1.857x + 96.788 = 24.37 

- 1.857x = 24.37 - 96.788

- 1.857x = - 72.418 

x = 72.418/1.857 = 38.997 

Rounding to the nearest whole number, 

x = 39 

It means that after 39 years after 1980, the monthly wireless phone bill is $24.37. 

Year = 1980 + 39 = 2019 

The answer is 2019. 

Answer: 

The average monthly wireless phone bill would be $24.37 in the year 2019.