find expected value, standard deviation, and probability
this is a homework help. I'm stumped as to which formula or chapter to look at. please show guidance. IM NOT ASKING FOR AN ANSWER, just guidance.
Q4. In a Gallup poll, 47% of the eligible women responding said that they would date a coworker. Suppose 350 employed women were selected at random.
a) What would be the expected value and standard deviation of the number of these women who would date a coworker?
b) What is the probability that at least 180 of them would date a coworker?
a) u = n*p = 380*0.47 = 178.6
s = square root ( n*p*q) = square root ( 380*0.47*0.53) = 9.7232
b) the "at least" is throwing me off. I have no idea how to start this.