Discussion:
Q: Safegate Foods, Inc., is redesigning the checkout lanes in its supermarkets throughout the country and is considering two designs. Tests on customer checkout times conducted at two stores where the new systems have been installed result in the following summary of the data.
Test at the .05 level of significance to determine whether the population mean checkout times of the two systems differ. Which system is preferred?
| System A |
System B |
| n1 = 120 |
n2 = 100 |
| xbar1 = 4.1 minutes |
xbar2 = 3.4 minutes |
| σ1 = 2.2 minutes |
σ2 = 1.5 minutes |