Question

1. Let x be the number of heads obtained in two tosses of a coin. The following table lists the probability distribution of x.
x 0 1 2
P(x) .25 .50 .25
Calculate the mean and standard deviation of x. Give a brief interpretation of the value of the mean.

Answer 1

Mean = 0(.25)+ 1(.50) + 2(.25)
Variance = 0^2(.25) + 1^2 (.50) + 2^2 (.25)

Sd = sqrt((variance - mean^2))
sd = sqrt(1.5- 1)= .7071067812