SAT Question 8193e8cd: Distributions, Center & Spread answer and explanation with Desmos solution

The mean of the list of numbers is found by dividing the sum of the numbers by the number of values in the list. Since there are $5$ numbers in the list, the mean is $\frac{1}{5}$ of the sum of the numbers. Note that 1/5, .2, .20, and 0.2 are examples of ways to enter a correct answer.