- #1
philipSun
- 9
- 0
Hi.
I choose randomly a one word, and I decided to choose a word blue. Let random variable x be a length of the word blue. What is expected value and variance of a word blue?
So, random variable x = 4.
E(X) = Ʃ xi fX(xi)
i:xi∈S
x1 + x2 + x3 + x4 = 10.
expected value = 10.
Variance is
Var(X) = E[X − E(X)]^2
Var(X) = E[10 − E(4)]^2 = 6^2 = 36
Variance = 36
I choose randomly a one word, and I decided to choose a word blue. Let random variable x be a length of the word blue. What is expected value and variance of a word blue?
So, random variable x = 4.
E(X) = Ʃ xi fX(xi)
i:xi∈S
x1 + x2 + x3 + x4 = 10.
expected value = 10.
Variance is
Var(X) = E[X − E(X)]^2
Var(X) = E[10 − E(4)]^2 = 6^2 = 36
Variance = 36