The mean waiting time at the drive through of a fast food

Last updated: 12/10/2023

The mean waiting time at the drive through of a fast food restaurant from the time an order is placed to the time the order is received is 87 6 seconds A manager devises a new drive through system that he believes will decrease wait time As a test he initiates the new system at his restaurant and measures the wait time for 10 randomly selected orders The wait times are provided in the table to the right Complete parts a and b below Click the icon to view the table of correlation coefficient critical values Yes the conditions are satisfied The normal probability plot is linear enough since the correlation coefficient is greater than the critical value In addition a boxplot does not show any outliers a Because the sample size is small the manager must verify that the wait time is normally distributed and the sample does not contain any outliers The normal probability plot is shown below and the sample correlation coefficient is known to be r 0 985 Are the conditions for testing the hypothesis satisfied Ho H 101 5 67 6 57 6 70 8 75 1 66 1 79 3 AExpected z score 2 1 80 4 96 7 84 9 60 75 90 105 Time sec O Q b is the new system effective Conduct a hypothesis test using the P value approach and a level of significance of 0 01 First determine the appropriate hypotheses 87 6 87 6 N