Question

A certain fast food restaurant 77.5% of customers ordered items from the value menu if 14 customers are randomly selected what's the probability that at probability least 9 customers ordered an item from the value menu?

Answer 1

Answer: 0.927

Step-by-step explanation:

Know that this is a binomial probability. In this case we want to find the probability of 9 to 14 success is inclusive where a successes a customer ordering from the value menu. This probability is the complement of the probability 0 to 8 successes inclusive. To determine the probability from a binomial distribution using Excel use the following steps. First press formulas and then insert function then select binomial distribution. Next enter the values for the number of successes, the number of trials, the number of success and the number of successes. In this case, enter 8, 14, and 0.775, in that order. Enter 1 for cumulative since this is a cumulative probability. Press OK. Excel should then display the probability. Here the resulting probability is 0.072766 which is 0.073 rounded to three decimal places. To find the probability of 9 to 14 customers ordering from the value menu subtract the previous probability from one. The probability is 1-0.073 which equals 0.927.