Question

Find the expected value and variance of the number of heads appearing when to fair coins are tossed

Answer 1

Answer:

1/2 ☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆

Answer 2

Answer:

The correct answer is 1/2.

Step-by-step explanation:

s = { HH, HT, TH, TT }

let, x = number of heads

so,

x =         0        1       2

p(x) =     1/4     2/4   1/4

mean =  (Σ pi * xi) = (1/4 * 0) + (2/4 * 1) + (1/4 * 2)

                           = 1

variance = (Σ pi * xi²)  - (Σ pi * xi)²

              =  [(1/4 * 0) + (2/4 * 1) + (1/4 * 4)] - 1²

              = 1/2