Question

An English instructor asserted that​ students' test grades are directly proportional to the amount of time spent studying. Lisa studies 6 hr for a particular test and gets a score of 78. At this​ rate, how many hours would she have had to study to get a score of 99​?
She would have had to study
nothing hr to get a score of 99.

Answer 1

To solve this problem we can set up a proportion.

$\frac{6}{78} = \frac{x}{99}$

Then cross multiply and divide.

99*6=594/78= 7.6.

Lisa would have had to study about 7.6 hours to get a score of 99.