Question

A survey found 70% of adults over 50 wear glasses. In a random sample of 10 adults over 50, what is the probability that exactly six wear glasses and at least six wear glasses

Answer 1

The probability of all events occurring is found by multiplying the probabilities of the individual events.

.7^6 * .3^4 = ? (exactly six)

Add probabilities of 6, 7, 8, 9 and 10 for "at least."

e.g., for 10 wearing = .7^10 = ?

for 9 wearing = .7^9 * .3 =?

I'll let you do the remaining calculations.