Question

Luis's math teacher plots student grades on their weekly quizzes against the number
of hours they say they study on the pair of coordinate axes and then draws the line of
best fit. What is the meaning of the x-value on the line when y = 75?

Answer 1

Answer:

In the graph, we have a linear fit of the student's grades as a function of the number of hours they say that they study.

Then the y-axis represents the grade, and the x-axis represents the number of hours of study, and because this is a linear fit, we will have something like:

y = a*x +b

If we input a value of x here (number of hours studied) we would get the expected grade for the weekly quiz y.

In this situation, the meaning of the x-value on the line when y = 75 would be the (adjusted) number of hours studied to get a grade of 75.

So this x-value is the average number of hours that a student needs to study to get a grade of 75 points.