1. The problem statement, all variables and given/known data coin tossed 70 times, find exact value for probability that number of heads is between 35 and 55 2. Relevant equations NA 3. The attempt at a solution P(heads) = 1/2; and then I am not sure.... edit: ok, maybe something like this: (1/2)*(35/70) - (1/2)*(55/70) ?? could someone confirm/correct? Thanks in advance.