A data scientist is analyzing customer satisfaction ratings for three different product versions, labeled Version 1, Version 2, and Version 3. The variable 'r' is used to denote a single customer's satisfaction rating. After collecting data, the data scientist calculates the average satisfaction rating for each version and finds that the average for Version 2 is 4.5 out of 5. Which of the following expressions correctly represents the average satisfaction rating for Version 2?

A company is analyzing the weekly sales performance of its different retail stores. Let the variable s represent the sales amount for a single transaction. If the stores are identified by a numerical index, the average weekly sales for store number 7 would be represented by the notation ____.

Interpreting Performance Metrics Notation