Erol's Darts

Difficulty: Easy · Topics: Probability, Statistics, Standard Deviation

Erol throws 10 darts in each round. The table shows how many hit the target in each round.

Round 1 2 3 4 5 --- --- --- --- --- --- Hits 8 2 2 8 5

What is the standard deviation of his hits?

(Use the standard deviation s=√(Σ (x i-bar x)^2)/(n-1).)