# 2.1Introduction

The purpose of this textbook is to teach the capabilities of the various functions and operations available in Excel’s data analysis toolbank. We begin with the more basic functions and then move on to more sophisticated capabilities in later chapters. In this lesson we will learn how to summarize data with aggregate functions with a special focus on Conditional aggregate functions. Conditional aggregate functions include the option to test criteria to see if values should be included or excluded in the rsult.

Aggregate functions in Excel provide the capability to apply a formula across multiple cells in a spreadsheet. The three types of aggregate functions that we illustrate in this section are:

• COUNT - Counts the number of valid values across a range a cells

• SUM - Adds the numeric values across a range of cells

• AVERAGE - Computes the numeric average or mean across a range of cells

Each of these functions operate over an specific range of cells that are identified in the function. Also, each of these three types of functions have several versions that constrain the way the data is evaluated.

In addition to the basic versions of these three functions, each one also has a conditional or logical version, which permits the user to include a specific criterion or multiple criteria to constrain the answer.

Also included in this lesson are various miscellaneous operations and function that are useful for doing data analytics. These miscellaneous functions will be used from time to time throughout the textbook.