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Science-Related Homework Help Statistics and Probability Topic started by: uni67 on Aug 30, 2019



Title: Time Wasted A group of students decide to see if there is link between wasting time on the internet ...
Post by: uni67 on Aug 30, 2019
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.


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.


Title: Time Wasted A group of students decide to see if there is link between wasting time on the internet ...
Post by: beunikuel on Aug 30, 2019
a. There is only a weak relationship. R2 = 13.8% and r = -0.372. The relationship seen on the scatterplot is very weak.
b. It appears there may be no relationship at all. The value -0.372 does not appear to be unusual. 15 out of 100 times the correlation was even closer to negative one. So the association we are observing could be due to random variation.


Title: Time Wasted A group of students decide to see if there is link between wasting time on the internet ...
Post by: uni67 on Aug 30, 2019
Brilliant