Consider the following study: Researchers recorded the temperatures at The Fashion
Mall at Keystone in Indianapolis during 40 random days in November and December 2013, then again in June and July 2014. For these same days, they recorded the mall sales. The correlation coefficient between these variables was -0.884 and it was significant at the 1% level. (Though we do not cover it in our course, the significance of the correlation coefficient can be tested with a t test.)
a. Interpret this correlation coefficient.
b. Does this correlation show that colder temperatures cause sales at malls to increase, or is something else the cause? (Hint: Consider the months during which the temperatures were recorded.) Briefly explain your answer.