She wants us to take our favorite team and figure out the probability of in a random year our team winning 10 games.

I am taking the win total for 10 years, 20 years, and 42 years. Then I will find the mean and standard deviation of the win totals. I will have 3 answers based on 10, 20, and 42 years.

My win totals: (yeah my team isn't real good lol)

10 year: 55 mean 5.5

20 year: 132 mean 6.6

42 year: 270 mean 6.4

I am confused on finding the standard deviation...

Am I going to take each of the seasons win totals minus the mean and square it...then add them all together and divide by n-1? (would that be 10-1 and then 20-1 and 42-1?)

hopefully this makes sense...I didn't see it completely necessary to write out all my data..let me know if it is needed.