Question

At a restaurant, 30% of customers donate to charity in exchange for a coupon. Estimate the probability that it will take at least four customers to find one who donates.

Answer 1

Answer:

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

Answer 2

Answer:

75.99%

Step-by-step explanation:

To calculate this, we can use complements. We can find, instead the probability that at least one will donate, the probability that not none of them will donate.

First, we can find the probability that none will donate, which will be (70%)^4, since the chance each will not donate is the same. From this we get 24.01%.

To find the probability that at least one donates, we do the complement:

100%-24.01%=75.99%