Question

Let X represent the difference between the number of heads and the number of tails when a coin is tossed 48 times. Then P(X=8)=

So far I got 0.05946 but it keeps telling me I'm wrong

Answer 1

when we toss a coin there is two outcomes. One head and one tail.

Let A be the number of heads

and B be the number of tails

When a coin is tossed 48 times then,

For the difference between the number of heads and the number of tails to be 8 when a coin is tossed 48 times is

or

on solving for A, which means either the number of heads is 28 or 20

so solving using the binomial probability distribution

probability of success: p = 0.5

the total number of trials: n= 48

P(X=8) = P(A=28) + P(A=20)