Binomial problems: Basic

Anita's, a fast-food chain specializing in hot dogs and garlic fries, keeps track of the
proportion of its customers who decide to eat in the restaurant (as opposed to ordering the
food "to go"), so it can make decisions regarding the possible construction of in-store play
areas, the attendance of its mascot Sammy at the franchise locations, and so on. Anita's
reports that 48% of its customers order their food to go. If this proportion is correct, what
is the probability that, in a random sample of 4 customers at Anita's, exactly 3 order their
food to go?

3 answers

This is a binomial distribution:

p = .48, q = 1 - p = .52

The probability P{X} of exactly 4 customers from 5, will order food to go is:

P{X = 4} = (5 C 4)((.48)^4)((1 - .48)^1)
0.37
Anita's, a fast-food chain specializing in hot dogs and garlic fries, keeps track of the proportion of its customers who decide to eat in the restaurant (as opposed to ordering the food "to go") so it can make decisions regarding the possible construction of in-store play areas, the attendance of its mascot Sammy at the franchise locations, and so on. Anita's reports that 45% of its customers order their food to go. Suppose that this proportion is correct and that a random sample of 40 individual customers is taken.
Estimate the number of customers in the sample who order their food to go by giving the mean of the relevant distribution (that is, the expectation of the relevant random variable). Do not round your response.
Quantify the uncertainty of your estimate by giving the standard deviation of the distribution. Round your response to at least three decimal places.