Question

What is the mean and standard deviation of 5, 10, 12, 15, 20?

Answer 1

The mean is 12.4 and the standard deviation is 5.004.

Explanation:

The mean is pretty easy to find. Just add all the numbers and then divide the sum of those numbers by how many numbers are in the data set:

`5+10+12+15+20=62//5=12.4`

12.4 is our mean. The standard deviation is a bit trickier. First, we must find the variance. To do that, we take the mean and subtract that from each number. We then square the result of each number and add them all together. Finally, we divide that by the sample space, (in this case, 5).

#((5-12.4)^2+(10-12.4)^2+(12-12.4)^2+(15-12.4)^2+(20-12.4)^2)/5=25.04 #

From here, it's simple. Just find the square root of the variance, and you have your standard deviation!

`sqrt(25.04)~~5.004`