Time Wasted a Group of Students Decide to See If

question 13

Essay

Time Wasted A group of students decide to see if there is link between wasting time on the internet and GPA. They don't expect to find an extremely strong association, but they're hoping for at least a weak relationship. Here are the findings.

$\begin{array}{|l|l|l|}\hline \text { linear regression results: }& & \\ \text { Dependent Variable: GPA} & & \\ \text { Sample size: 10 }& & \\ \text { R (correlation coefficient) }=-0.37199274 & & \\ \text { R-sq =0.1383786 } & & \\\mathrm{~s}=0.85365134 & & \\& & \\ \text { Parameter }& \text { Estimate} & \text { Std. Err.} \\\hline \text { Intercep}t & 4.06191 & 0.74405 \\\hline \text { Hours/week} & -0.0297 & 0.02616 \\\hline\end{array}$

a. How strong is the relationship the students found? Describe in context with statistical justification.
One student is concerned that the relationship is so weak, there may not actually be any relationship at all. To test this concern, he runs a simulation where the 10 GPA's are randomly matched with the 10 hours/week. After each random assignment, the correlation is calculated. This process is repeated 100 times. Here is a histogram of the 100 correlations. The correlation coefficient of -0.371 is indicated with a vertical line.
b. Do the results of this simulation confirm the suspicion that there may not be any relationship? Refer specifically to the graph in your explanation.

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Definitions:

Credit Price

The cost associated with borrowing money or purchasing goods and services on credit, including interest and fees.

Discount Percent

The percentage by which the price of an item is reduced from its original price.

Percentage Cost

The cost of something expressed as a percentage of another amount, often used in calculating interest rates, commissions, or efficiency ratios.

Credit Report

A detailed report of an individual's credit history prepared by a credit bureau, used by lenders to determine creditworthiness.