Based upon statistical studies it has been found that 3.36% of all births in the United States will result in...

Based upon statistical studies it has been found that 3.36% of all births in the United States will result in twins being born. If 32,300 births are selected at random what is the probability that:

a) between 1,000 and 1,100 of them (inclusive) will result in twins being born?

b) at most 1,125 of them will result in twins being born?