the variance of a sample is reported to be 144. the sum of squared deviation from sample mean is 7200. the sample size is

Little's law can be applied to any part of the store, such as a particular department or the checkout lines. the store owner determines that, during business hours, approximately 84 shoppers per hour make a purchase and each of these shoppers spend an average of 5 minutes in the checkout line. at any time during business hours, about how many shoppers, on average, are waiting in the checkout line to make a purchase at the good deals store?