Question

A student is assessing the correlation between the average number of hours of internet browsing and average score on a math test. The table below shows the data:


Number of hours of internet browsing
(x) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Score on math test
(y) 95 94 93 92 91 90 89 88 87 86


Part A: Is there any correlation between the average number of hours of internet browsing and average score on the math test? Justify your answer. (4 points)

Part B: Write a function which best fits the data. (3 points)

Part C: What does the slope and y-intercept of the plot indicate? (3 points)

Answer 1

Looking at the numbers, it does seem like there is a correlation between hours of internet and the test scores. Every extra half-hour actually seems correlated to one less point on the test score.
The function would want to take into account how the test score starts, with 0 hours of internet browsing, and also represent how that changes with every additional hour spent.
So, at 0 hours, the test score average is 95, but with every additional hour, that score goes down by 2.
And this is related to the equation from part B: the slope would represent the change in test score with each additional hour of internet browsing, and the y-intercept would represent the average score with 0 hours of internet browsing