The rule of the mean is
Mean = sum/number
The given data is
30, 34, 32, 31, 34, 39, 36, 30, 32, 34, 38, 39, 35, 37, 38
There are 15 numbers, then
The number = 15
We will add all of them to find the sum
[tex]\begin{gathered} S=30+34+32+31+34+39+36+30+32+34+38+39+35+37+38 \\ \\ S=519 \end{gathered}[/tex]The sum = 519
Then divide it by 15 to find the mean
[tex]\begin{gathered} Mean=\frac{519}{15} \\ \\ Mean=34.6 \end{gathered}[/tex]The mean is 34.6
