Question

The graduation rate of a local high school is growing at a rate which can be estimated by thefollowing linear model, where y represents the graduation rate, as a percentage, x yearsafter2017.y = 74.18 +1.57%Use the model to predict the first year in which the school will exceed a 90% graduation rate.

Answer 1

Problem

The graduation rate of a local high school is growing at a rate which can be estimated by the

following linear model, where y represents the graduation rate, as a percentage, x years

after

2017.

y = 74.18 +1.57x%

Use the model to predict the first year in which the school will exceed a 90% graduation rate.

Solution

For this case we want to find where y>90

So then we can do the following:

74.18 + 1.57 x > 90

1.57 x> 90-74.18

1.57 x > 15.82

And dividing by 1.57 we got:

x > 10.076

So then approximately after 2027 they would have a graduation rate higher than 90%