A fair coin is tossed once.If the random variable x is the number of heads that show up,

Question

Calculate

1.the mean of the random Variable

2.the variance

Answer 1

This is a binary situation because there are only two possibilities: head or tail.

If n=number of tosses, the mean is np and the variance is np(1-p), where p is the probability of a head.

If n=1 and p=1/2, the mean is 0.5 and the variance 0.5*0.5=0.25.

I think!