Solve the Problem $$\begin{array} { | c c c c | } \hline 500 & 750 & 630 & 480 \\550 & 650 & 720 & 780 \\820 & 960 & 1200 & 770 \\\hline\end{array}$$

Essay

Solve the problem.
-The weekly incomes (in dollars) of a sample of 12 nurses working at a Los Angeles hospital are given below. $$\begin{array} { | c c c c | } \hline 500 & 750 & 630 & 480 \\550 & 650 & 720 & 780 \\820 & 960 & 1200 & 770 \\\hline\end{array}$$