Stats help pliz?

The Gold Credit card company knows that 70% of its customers are males. The company plans to promote its credit card by selecting a random sample of 5 customers each month and offering them a free vacation.





(a)What is the probability that in a given month all five selected customers are males?


(b)What is the probability that in a given month all five selected customers are females?


(c)What is the probability that the selected sample of 5 customers includes at least female?


(d)What is the mean number of male customers who are likely to be selected in the coming month?

Stats help pliz?
a.) (.70)(.70)(.70)(.70)(.70) = .7^5 = .168 or 16.8% chance





b.) (1-.7)=percentage of NOT male customers=.3


(.3)^5=.00243 or .243%





c.) the chance of AT LEAST one = 1 - chance of NONE


So the chance of No Females is the chance of ALL MALES, .168 (part a)


1-.168=.832, or 83.2%