Answer:
1.43%
Explanation:
we have that we can solve it by means of binomial, in this case m = 25. Also the probability of head is 50%. we need to know when it falls 7 times, therefore x = 7
the formula is:
P (x) = mCx * p ^ x * q ^ (m-x)
we know that p is 0.5 therefore q is equal to 0.5, replacing:
P (7) = 25C7 * 0.5 ^ 7 * 0.5 ^ (25-7)
P (7) = 25! / (7! * (25-7)!) * 0.5 ^ 7 * 0.5 ^ (25-7)
P = 0.0143
that is, the probability is 1.43%