Waikato Environment for Knowledge Analysis (WEKA):
Start Weka GUI.
Click Explorer Button to start the Weka Explorer.
Download regression data from the Weka DataSet page:
Copy and unzip it to the data directory under the directory where the Weka was installed, like "C:\Program Files\Weka-3-8\".
Click Open file Button to open a data file
Find the directory "C:\Program Files\Weka-3-8\data\datasets-numeric\numeric\"
Then select the "autoMpg.arff" to find out a regression model to predict the miles per gallon (MPG) for a car.
Weka loads the data and shows Attributes of this data file.
Click the "Classify" tab on upper side of the window.
Click "Choose" button within the Classifier area.
Select LinearRegression under the branch of the tree "weka-classifiers-functions".
Click the Start button.