Activity Overview
Students perform single and two-sample t procedures to investigate special cases of normally distributed data. They explore inference for a least-square regression line, including the confidence interval.

Before the Activity
Install the Statistics with List Editor application 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 163 - 181 from the attached PDF file for your class

During the Activity
Distribute the pages to the class.
Follow the Activity procedures:
Single-Sample t Procedure:

Create lists and enter functions to plot a normal distribution, and t distributions
Note that the peak of the Normal distribution is highest, and the tails of the t distribution are larger than the normal distribution
Enter sample data and analyze its distribution
Graph a normal probability plot and examine the linearity of the points
Decide on the type of distribution
Calculate the t value, Confidence Interval, and the Margin of Error
Find the p-value and evaluate the hypothesis
Two-Sample t Procedures:

Enter two sets of data as a list, the size of one sample 1 being less than the other
Find the 90% confidence interval for the difference in the means of the data sets
Observe that pooled and nonpooled results are similar because their degrees of freedom are close
Note that if degrees of freedom are not close, the nonpooled result should be considered
Determine the p-value and evaluate the hypothesis
Inference for Least-Square Regression Line:

Enter the weight of the car and its mileage per gallon data as lists and check for a linear relationship between them
Perform a Linear Regression T Test
Test the hypothesis by determining the p-value and determine the regression equation
Check the validity of the t-test by setting up a normal probability plot of residuals
Find the 90% confidence interval for the slope of the regression line
Estimate the mean for normal data and transformed data
Check residuals for transformed data

After the Activity
Review student results:

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