Using addition of variables, it is found that the mean of S is of 73 and the standard deviation is of 8.5.
<h3>What happens to the mean and the standard deviation when two variables are added?</h3>- The mean is the sum of the means.
- The standard deviation is the square root of the sum of variances.
In this problem, for variables A and B, we have that:
Variable S is the sum of A and B, hence:
The mean of S is of 73 and the standard deviation is of 8.5.
More can be learned about addition of variables at brainly.com/question/26156502