Final answer:
To calculate the probability that more than 9 shoppers out of 45 will say they are likely to purchase reusable cloth bags for groceries, we can use the binomial probability formula. The probability is approximately 80%.
Step-by-step explanation:
To calculate the probability that more than 9 shoppers out of 45 will say that they are likely to purchase reusable cloth bags for groceries, we can use the binomial probability formula. The formula is:
P(X > k) = 1 - P(X ≤ k)
where P(X > k) is the probability that X is greater than k, P(X ≤ k) is the probability that X is less than or equal to k, and X follows a binomial distribution with parameters n (number of trials) and p (probability of success in each trial).
In this case, n = 45 and p = 0.33 (33%). We want to calculate:
P(X > 9) = 1 - P(X ≤ 9)
Using a binomial probability calculator, we find that P(X ≤ 9) is approximately 0.190295. Therefore, P(X > 9) ≈ 1 - 0.190295 = 0.809705, which is approximately 80.97%.
Therefore, the correct answer is a. 80%.