Answer:
Kate has encountered the Simpson's Paradox. This paradox occurs when the relationship between two variables is reversed when they are analyzed together compared to when they are analyzed separately. In this case, pepperoni pizza is the most popular flavor when analyzed separately for weekdays and weekends, but overall it is not the most popular flavor. This paradox can occur when there are other factors that are not being taken into account, such as the total number of sales for each flavor.
Step-by-step explanation: