91Ó°ÊÓ

In mathematics, the average of a number of observations is called mean of the data set.

The mean is the same as the average value of a data set and is found using a calculation. Add up all of the numbers and divide by the number of numbers in the data set.

How to Find the Mean

By adding all data values to get the sum, and then count the number of values in your data set. At last divide the sum by the count.

We can write: Mean =$\frac{\text{Sumofallobservations}}{\text{Numberofobservation}}$

$Mean  of  observation=\frac{Sum  of  observation}{Number  of  observation}$

Mean temperature

$=\frac{\left(-  {15}^{0}F\right)+\left(-  7^{0}F\right)+\left(8^{0}F\right)+\left(3^{0}F\right)+\left(-  9^{0}F\right)}{5}$

$=\frac{-{15}^{0}F-7^{0}F-9^{0}F+8^{0}F+3^{0}F}{5}  =  \frac{-  (  {15}^{0}F+7^{0}F+9^{0}F  )  +8^{0}F+3^{0}F}{5}$

$=\frac{-{31}^{0}F+{11}^{0}F}{5}  =  \frac{-  {20}^{0}F}{5}  =  -  4^{0}F$

Mean temperature is $  -  4^{0}F$