Question

If the population mean payment time is 19.5 days, what is the probability of observing a sample mean payment time of 65 invoices less than or equal to 18.1077 days?

Answer 1

Answer: P(mean x<18.1077) = P(z< -2.67) = 0.0038

Explanation:

Value of Z for 18.1077 = (18.1077 - 19.5)/0.5209 = -2.67