Customers a one Super Market have a choice when paying for their groceries. They may check out and pay using the standard cashier assisted checkout, or they may use the new U- Scan procedure The store manager would like to know if the mean checkout time using the standard checkout method is longer than using the- Scan at the.01 significance level, she gathered the following sample information. The time is measured from when the customer enters the line until their bags are in the cart.