5. Introducing Statistics

Question 1

Population mean

Answer 1

μ = 1/N (the sum from i=1 to N) yi

Question 2

Population variance (2 ways)

Answer 2

σ^2 = 1/N (the sum from i=1 to N) (yi - μ)^2

= 1/(n-1) { (the sum from i=1 to N of xi^2) - nx(bar)^2}

Question 3

Sample mean

Answer 3

x(bar) = 1/n (the sum from i=1 to N) xi

Question 4

Sample variance

Answer 4

s^2 = 1/(n-1) (the sum from i=1 to N) (xi - x(bar)^2)