Question

The waiting time to check out of a supermarket has had a population mean of 9.17 minutes.​ Recently, in an effort to reduce the waiting​ time, the supermarket has experimented with a system in which there is a single waiting line with multiple checkout servers. A sample of 50 customers was​ selected, and their mean waiting time to check out was 7.31 minutes with a sample standard deviation of 4.3 minutes.

At the 0.01 level of​ significance, using the​ p-value approach to hypothesis​ testing, is there evidence that the population mean waiting time to check out is less than 9.17 ​minutes?

P-value for this test is 0.0018.

Interpret the meaning of the​ p-value in this problem. Choose the correct answer below.

(A) The​ p-value is the probability of obtaining a sample whose mean is 7.31 minutes or​ less, assuming the population mean is greater than or equal to 9.17 minutes.

(B) The​ p-value is the probability of obtaining a sample whose mean is 7.31 minutes or​ greater, assuming the population mean is greater than or equal to 9.17 minutes.

(C) The​ p-value is the probability of obtaining a sample whose mean is 7.31 minutes or​ less, assuming the population mean is less than 9.17 minutes.

Which one is the correct one?

Answer 1

option A is correct one

(A) The​ p-value is the probability of obtaining a sample whose mean is 7.31 minutes or​ less, assuming the population mean is greater than or equal to 9.17 minutes.