Recall that the mean of a given set of numbers is the sum of the numbers divided by the number of numbers, therefore, the mean of the dataset is:
[tex]\bar{x}=59.54.[/tex]Now, the range of a data set is the difference between the maximum and the minimum, in this case, the maximum is 99, and the minimum is 15 therefore, the range is:
[tex]99-15=84.[/tex]Finally, the standard deviation is given by the following formula:
[tex]s=\frac{1}{N-1}\sum(x_i-\bar{x})^2,[/tex]where N is the sample size, x_i is an element of the set, and x^- is the mean. The standard deviation of the set is:
[tex]s=24.35.[/tex]