Over the 365 days of any year in any major city, the greater the quantity of ice cream sold, the greater the number of murders.
(a) What is the direction of this correlation?
(b) Does this correlation prove that eating ice cream drives people to violence? Why or why not?
(c) Explain the correlation without assuming a causal connection between the two variables.
(d) Which part of Figure 7.9 does your explanation illustrate?