# Activities

• • • ##### Subject Area

• Math: Statistics: Inferential Statistics

• ##### Author 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 11 from the EXPLORATIONS Book:
Statistics Handbook for the TI-83

## Inference for Correlation and Regression

#### Activity Overview

In this activity, students test if a significant relationship exists between a bivariate data set, and then calculate the confidence and predictive intervals. They also improve the interval-prediction capabilities by automating the process.

#### Before the Activity

Download the A2MULREG 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 115 - 124 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

Inference for Correlation and Regression:

• Record data of hours of study outside class and final grade
• Enter the data as lists
• Set up a scatter plot
• Determine the equation of the regression line
• Calculate the correlation coefficient and the coefficient of determination
• Find the p-value
• Test the hypothesis
• Find the confidence interval for β
• Plot the data and the regression line
• Calculate the residuals and residual plots
• Set up another scatter plot
• Find the predictive and confidence intervals for the critical t-value
• Compare the two intervals

• Multiple Regression:
• Store the data in a matrix
• Run the A2MULREG program to automate the above process and to improve the prediction capability of the multiple regression equation
• #### After the Activity

Review student results:

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