Question

find a. the mean; b. the deviation from the mean for each data item; and c. the sum of the deviations in part (b) for the following group of data items. 65, 75, 70, 65, 80 a. the mean is (simplify your answer.)

Explanation:

Step1: Calculate the mean

The formula for the mean $\bar{x}$ of a data set $x_1,x_2,\cdots,x_n$ is $\bar{x}=\frac{\sum_{i = 1}^{n}x_i}{n}$.
Here, $n = 5$, $x_1=65$, $x_2 = 75$, $x_3=70$, $x_4=65$, $x_5 = 80$.
$\sum_{i=1}^{5}x_i=65 + 75+70+65+80=355$.
$\bar{x}=\frac{355}{5}=71$.

Answer:

$71$