5b let random variable x represent the number of heads minus the number of tails when a fair coin is tossed 9 times.
what is pr(x=0)?
what is pr(x=3)?
let random variable y represent the number of heads minus the number of tails when a fair coin is tossed 8 times.
what is pr(y=0)?
what is pr(y=3)?

Let be the number of times a coin lands heads up. Then the coin lands tails up times, and . follows a binomial distribution with and , so that

Then we have

because can only take on integer values. The other probability is

In terms of , we have and follows a binomial distribution with and the same probability as before, so that

Then we find

and

2

step-by-2step explanation: