Variance of a fair 6-sided die?
Variance of a fair 6-sided die?
Approach: E[X^2] - (E[X])^2.
35/12. E[X]=3.5, E[X^2]=91/6. 91/6 - 49/4 = 35/12.
Follow-up: What is the standard deviation?
Key concepts: moments.
Variance of a fair 6-sided die?
Approach: E[X^2] - (E[X])^2.
35/12. E[X]=3.5, E[X^2]=91/6. 91/6 - 49/4 = 35/12.
Follow-up: What is the standard deviation?
Key concepts: moments.