## Algebra 2 (1st Edition)

The mean of $n$ numbers is the sum of the numbers divided by $n$. The median of $n$ is the middle number of the numbers when they are in order (and the mean of the middle $2$ numbers if $n$ is even). The mode of $n$ numbers is the number or numbers that appear(s) most frequently. Hence here the mean: $\frac{192100+195800+199900+201900+ 205200+ 210300+ 215500 }{7}=202957.142$. The median is the middle item in the sequence $192100,195800;199900; 201900; 205200; 210300; 215500$, which is: $201900$. There is no mode because all items appear the same number of times. The range is the difference between the largest and the smallest data value. The standard deviation of $x_1,x_2,...,x_n$ is (where $\overline{x}$ is the mean of the data values): $\sqrt{\frac{(x_1-\overline{x})^2+(x_2-\overline{x})^2+...+(x_n-\overline{x})^2}{n}}$. Hence here the range is: $215500-192100=23400$, and the standard deviation is: $\sqrt{\frac{(192100-202957.142)^2+(195800-202957.142)^2+...+(215500-202957.142)^2}{7-1}}\approx8122.4$