Using the binomial distribution, it is found that there is a 0.056 = 5.6% probability that more than 7 will make a purchase.
<h3>What is the binomial distribution formula?</h3>The formula is:
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- There are 12 customers, hence n = 12.
- The probability of any of them making a purchase is of p = 0.4.
The probability that more than 7 will make a purchase is given by:
P(X > 7) = P(X = 8) + P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12).
Hence:
Then:
P(X > 7) = P(X = 8) + P(X = 9) + P(X = 10) + P(X = 11) + P(X = 12) = 0.042 + 0.012 + 0.02 + 0 + 0 = 0.056.
0.056 = 5.6% probability that more than 7 will make a purchase.
More can be learned about the binomial distribution at brainly.com/question/24863377