Section C Section C Checkpoint

Problem 1

During the autumn, a Canadian city’s number of flu cases and sales of sandals are recorded. A linear model is fit with a correlation coefficient of r=-0.24r = \text-0.24.
  1. Classify the relationship as strong or weak and as positive or negative.
  2. Do you think the relationship is causal? Explain your reasoning.
Show Solution
Solution
  1. There is a weak, negative correlation.
  2. Sample response: The relationship is likely not causal. As the temperature gets cooler, people usually buy fewer sandals and spend more time indoors with one another, spreading flu germs. The temperature is most likely the cause of both of these variables changing rather than one directly causing the other to change.
Show Sample Response
Sample Response
  1. There is a weak, negative correlation.
  2. Sample response: The relationship is likely not causal. As the temperature gets cooler, people usually buy fewer sandals and spend more time indoors with one another, spreading flu germs. The temperature is most likely the cause of both of these variables changing rather than one directly causing the other to change.