What's the probability that at least 4 out of the next 20 customers will buy cake pops? (Hint: remember to show the setup!)

Question

Lindsay knows 48% of people who walk into her dessert show will buy cake pops.

Answer 1

we are dealing with a binomial distribution and will use the binomial formula to compute the probability

P(x = k) = n!/(k!(n-k)!) p^k (1-p)^(n-k)

where:

x = number of customers that buy cake pops

n = total number of customers

p = probability customer buys a cake pop

for k = 4, n = 20, p = 0.48 above formula becomes:

20!/(4!16!) (0.48)^4 * (0.52)^16 = 0.007