"Records at the College of Engineering show that 62% of all freshman who declare EE (electrical engineering) as their intended major field of study eventually graduate with an EE major. This fall, the College of Engineering has 316 freshmen who have declared a EE major. What is the probability that between 200 and 225 of them (including 200 and 225) will graduate with an EE major?"

The examples I have in my book have a standard deviation known for a problem like this, however there is no standard deviation given. Need some help with this one.