#### Overview of this book

Data Forecasting and Segmentation Using Microsoft Excel guides you through basic statistics to test whether your data can be used to perform regression predictions and time series forecasts. The exercises covered in this book use real-life data from Kaggle, such as demand for seasonal air tickets and credit card fraud detection. You’ll learn how to apply the grouping K-means algorithm, which helps you find segments of your data that are impossible to see with other analyses, such as business intelligence (BI) and pivot analysis. By analyzing groups returned by K-means, you’ll be able to detect outliers that could indicate possible fraud or a bad function in network packets. By the end of this Microsoft Excel book, you’ll be able to use the classification algorithm to group data with different variables. You’ll also be able to train linear and time series models to perform predictions and forecasts based on past data.
Preface
Part 1 – An Introduction to Machine Learning Functions
Free Chapter
Chapter 1: Understanding Data Segmentation
Chapter 2: Applying Linear Regression
Chapter 3: What is Time Series?
Part 2 – Grouping Data to Find Segments and Outliers
Chapter 4: Introduction to Data Grouping
Chapter 5: Finding the Optimal Number of Single Variable Groups
Chapter 6: Finding the Optimal Number of Multi-Variable Groups
Chapter 7: Analyzing Outliers for Data Anomalies
Part 3 – Simple and Multiple Linear Regression Analysis
Chapter 8: Finding the Relationship between Variables
Chapter 9: Building, Training, and Validating a Linear Model
Chapter 10: Building, Training, and Validating a Multiple Regression Model
Part 4 – Predicting Values with Time Series
Chapter 11: Testing Data for Time Series Compliance
Chapter 12: Working with Time Series Using the Centered Moving Average and a Trending Component
Chapter 13: Training, Validating, and Running the Model
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# Statistical significance of the slope

Remember that the slope determines the relationship between the X and Y variables.

To check the significance of the slope of the variables' relationship and the viability to build a predictive model, we are going to use the t-test. The t-test requires two hypotheses:

• H0 – null hypothesis: The slope equals zero. This means that there is no relationship between the variables.
• HA – alternative hypothesis: The slope is NOT equal to zero. This means that the variables have a relationship.

The t-test calculation steps are as follows:

1. Calculate the s value by dividing the SSE by the number of data elements minus two. In this example, the number of elements of data is 159.
2. Divide the slope by the s value.
3. Check whether the t-test is greater than the critical value given by the t-test table (https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf). If the value is greater than the critical...