Question

A large national survey shows that the waiting times for fast food restaurants is approximately normally distributed with a mean of μ = 4.2 minutes and a standard deviation of σ = 0.9 minutes. A fast food company claims that their mean waiting time in line is less than 4.2 minutes. To test the claim, a random sample of 95 customers is selected, and is found to have a mean of 3.7 minutes. We will use this sample data to test the fast food outlet's claim at a significance level of α = 0.05.

a) Set up hypotheses Ho and Ha to test the company’s claim.

Go to STAT >> TESTS, and choose Z-test – select the STATS option and enter the given sample information.

b) State the test statistic and p-value given by the calculator.

c) Compare the p-value to  = .05. State the appropriate decision (either Reject Ho or Fail to reject Ho), along with an explanation.

d) What can we conclude about the researcher’s claim? Explain your answer

Answer 1