Chapter 4.5, Problem 25E

To determine

To describe: A data-set that has a strong relationship that has a strong correlation but doesn’t have a causal relationship.

Answer to Problem 25E

The data set interprets as the no. of sweaters are sold in larger no., the sale of hot chocolate drinks also tends to increase, there is a strong positive correlation between them.

Explanation of Solution

Given information: Data set should have strong positive correlation but not causal relationship.

  $\begin{array}{lllllll}\mathrm{No}.ofsweaterssold\hfill & 20\hfill & 25\hfill & 27\hfill & 35\hfill & 40\hfill & 50\hfill \\ \mathrm{No}.ofhotchocodrinkssold\hfill & 100\hfill & 120\hfill & 137\hfill & 152\hfill & 170\hfill & 188\hfill \end{array}$

The above shown data is of a mall, it is the time when winter is approaching and the temperature is dropping day by day. It can observed that as more sweaters sell more hot chocolate drinks also tend to sell more, there is a strong positive correlation between them. But the relationship is not causal because increased sale of sweaters is not ‘causing’ more hot chocolate drinks to sell. The actual ‘cause’ is arrival of winter whose ‘effect’ is increased sale of winter-friendly items.