Question

Jesse collects data on his math scores on the last 12 tests and the number of hours he spent completing his math homework assignments and studying in the week before every test. He creates a scatter plot to show the data. The regression line shown on the graph best models the data on the scatter plot.

Based on the given model, how many hours in the week before the test does Jesse need to study to get a score of 90 on the test? Round your answer to the nearest hour.

Answer 1

• 24 hours

Explanation:

Using the two points on the regression line, let's find its equation.

Points:

• (0, 30) and (8, 50)

The slope:

• (50 - 30)/8 = 2.5

The y-intercept is

• 30

The equation:

• y = 2.5x + 30

Solve for x if y = 90

• 90 = 2.5x + 30
• 2.5x = 60
• x = 60/2.5
• x = 24

The answer is 24 hours