Education Technology

Activities

• Subject Area

• Math: Statistics: Inferential Statistics

9-12

60 Minutes

• Device
• TI-83
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• Accessories

TI Connectivity Cable

• Other Materials
This is Activity 12 from the EXPLORATIONS Book:
Statistics Handbook for the TI-83

Forecasting

Activity Overview

Students use regression to forecast values from a data. They study exponential smoothing. They also use the program FORECAST to automate a multiplicative model.

Before the Activity

Download the FORECAST program on the calculator using one of these two methods:

• TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
• TI-Navigator™  "send to class" feature
• See the attached PDF file for detailed instructions for this activity
• Print pages 125 - 132 from the attached PDF file for your class
• During the Activity

Distribute the pages to the class.

• Enter the data that represents the number of customers for a business over a set time period as lists
• Set up the calculator and graph an xy line plot
• Study the modeling equation
• Calculate the forecast for a period
• Determine the Mean of the Squared Errors and the Mean of the Absolute Values of Deviation for different values of the smoothing constant, α
• Trace the plot of the original data with the exponentially smoothed values through it
• Use the EXSMOOTH program to automate the above process
• Run the FORECAST program to calculate data for a multiplicative model
• Plot graphs for the original and deseasonalized data
• Perform a linear regression
• Determine the trend line and the slope
• After the Activity

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary