Random Sample: Each member of the entire population has an equal chance of being selected. Simple Random Sample: You can select groups of size n from the entire population, and every possible group has the same chance of being selected.
The mean of the answer is 20.5 because you add all of the number together and divide by 6 because there's 6 numbers. I'm sorry, but I don't know how to do the standard deviation... Hope this helped!
