Answer: 41.
Step-by-step explanation: To find the mean of a data set, you first need to add all the numbers together. It should look like this:
28 + 40 + 53 + 39 + 45 = 205.
The next step is to divide 205 by how many numbers you have in the data set. In this case, you have 5 numbers in the data set. Your work should look like this:
205 / 5 = 41.
Therefore, the mean of the data set is 41.
Hope this helps! :)