Chapter 3.1, Problem 3SP

To determine

The difference between the number of clients in month $12$ and month $1$. Where the following table represents the number of clients admitted to a drug and alcohol rehabilitation program over a $12-$ month period,

$\begin{array}{lll}\hfill & \text{Month}\hfill & \text{Number of clients}\hfill \\ \text{Jan}\text{.}\hfill & 1\hfill & 55\hfill \\ \text{Feb}\text{.}\hfill & 2\hfill & 62\hfill \\ \text{March}\hfill & 3\hfill & 64\hfill \\ \text{April}\hfill & 4\hfill & 60\hfill \\ \text{May}\hfill & 5\hfill & 70\hfill \\ \text{June}\hfill & 6\hfill & 73\hfill \\ \text{July}\hfill & 7\hfill & 77\hfill \\ \text{Aug}\text{.}\hfill & 8\hfill & 80\hfill \\ \text{Sep}\text{.}\hfill & 9\hfill & 80\hfill \\ \text{Oct}\text{.}\hfill & 10\hfill & 74\hfill \\ \text{Nov}\text{.}\hfill & 11\hfill & 85\hfill \\ \text{Dec}\text{.}\hfill & 12\hfill & 90\hfill \end{array}$