The MacBurger restaurant chain claims that the waiting time of customers for service is
normally distributed, with a mean of 3 minutes and a standard deviation of 1 minute. The
quality-assurance department found in a sample of 50 customers at the Warren Road
MacBurger that the mean waiting time was 2.75 minutes. At the .05 significance level, can
we conclude that the mean waiting time is less than 3 minutes?
Ho: The mean waiting time is 3 minutes
Ha:The mean waiting time is less than 3 minutes.
Z = ( 2.75 - 3) / 1/ √50
Z = -1.77
At 0.05 level the table value is -1.645
Since the calculated value lies in the rejection region, we reject Ho.
The mean waiting time is less than 3 minutes.
This posting presents testing of hypothesis that the waiting time of customers at MacBurger Restaurant for service is less than 3 minutes.