IQ and physical characteristics

• Create a simple matrix of scatter plots.
• Perform a linear regression analysis of PIQ on Brain, Height, and Weight.
• Click "Options" in the regression dialog to choose between Sequential (Type I) sums of squares and Adjusted (Type III) sums of squares in the Anova table.

Underground air quality

• Create a simple matrix of scatter plots.
• Select Graph > 3D Scatterplot (Simple) to create a 3D scatterplot of the data.
• Perform a linear regression analysis of Vent on O2 and CO2.
• Click "Options" in the regression dialog to choose between Sequential (Type I) sums of squares and Adjusted (Type III) sums of squares in the Anova table.

Soapsuds example (using matrices)

• Perform a linear regression analysis of suds on soap.
• Click "Storage" in the regression dialog and check "Design matrix" to store the design matrix, X.
• To create X^T: Select Calc > Matrices > Transpose, select "XMAT" to go in the "Transpose from" box, and type "M2" in the "Store result in" box.
• To calculate X^TX: Select Calc > Matrices > Arithmetic, click "Multiply," select "M2" to go in the left-hand box, select "XMAT" to go in the right-hand box, and type "M3" in the "Store result in" box. Display the result by selecting Data > Display Data.
• To calculate X^TY: Select Calc > Matrices > Arithmetic, click "Multiply," select "M2" to go in the left-hand box, select "suds" to go in the right-hand box, and type "M4" in the "Store result in" box. Display the result by selecting Data > Display Data.
• To calculate (X^TX)^-1: Select Calc > Matrices > Invert, select "M3" to go in the "Invert from" box, and type "M5" in the "Store result in" box. Display the result by selecting Data > Display Data.
• To calculate b = (X^TX)^-1X^TY: Select Calc > Matrices > Arithmetic, click "Multiply," select "M5" to go in the left-hand box, select "M4" to go in the right-hand box, and type "M6" in the "Store result in" box. Display the result by selecting Data > Display Data.

Heart attacks in rabbits

• Perform a linear regression analysis of Infarc on Area, X2 (early cooling), and X3 (late cooling).
• Click "Storage" in the regression dialog and check "Fits" to store the fitted (predicted) values.
• To create a scatterplot of the data with points marked by group and three lines representing the fitted regression equation for each group:
  • Select Calc > Calculator, type "FITS_1" in the "Store result in variable" box, and type "IF('Group'=1,'FITS')" in the "Expression" box. Repeat for FITS_2 (Group 2) and FITS_3 (Group 3).
  • Create a basic scatter plot but select "With Groups" instead of "Simple." Select Infarc as the "Y variable," Area as the "X variable," and Group as the "Categorical variable for grouping."
  • Select Editor > Add > Calculated Line and select "FITS_1" to go in the "Y column" and "Area" to go in the "X column." Repeat for FITS_2 (Group 2) and FITS_3 (Group 3).

Student heights and GPAs

• Perform a linear regression analysis of gpa on height.
• Create a fitted line plot to create a scatterplot of the data with a fitted simple linear regression line. Select Editor > Add > Reference Lines to add a horizontal line at the mean of gpa.
• SSE for the full model is in the SSE row of the Anova table.
• SSE for the reduced model is in the Total row of the Anova table.
• The overall F statistic and p-value are in the Regression row of the Anova table.

Skin cancer mortality

• Perform a linear regression analysis of Mort on Lat.
• Create a fitted line plot to create a scatterplot of the data with a fitted simple linear regression line. Select Editor > Add > Reference Lines to add a horizontal line at the mean of Mort.
• SSE for the full model is in the SSE row of the Anova table.
• SSE for the reduced model is in the Total row of the Anova table.
• The overall F statistic and p-value are in the Regression row of the Anova table.

Alcoholism and muscle strength

• Perform a linear regression analysis of strength on alcohol.
• SSE for the full model is in the SSE row of the Anova table.
• SSE for the reduced model is in the Total row of the Anova table.
• The overall F statistic and p-value are in the Regression row of the Anova table.

Allen cognitive level study

• Perform a linear regression analysis of ACL on:
  • Vocab (with default adjusted sums of squares).
  • Vocab and SDMT (with adjusted sums of squares).
  • Vocab and SDMT (click "Options" to switch to sequential sums of squares).
  • SDMT (click "Options" to switch back to adjusted sums of squares).
  • SDMT and Vocab (with adjusted sums of squares).
  • SDMT and Vocab (click "Options" to switch to sequential sums of squares).
  • SDMT, Vocab, and Abstract (with sequential sums of squares).

Heart attacks in rabbits (revisited)

• Perform a linear regression analysis of Infarc on:
  • Area, X2, and X3 (with default adjusted sums of squares).
  • Area.
  • Area, X2, and X3 (click "Options" to switch to sequential sums of squares).
• Find an F-based P-value.

Pastry sweetness

• Create a correlation matrix.
• Create a basic scatterplot.
• Perform a linear regression analysis of Rating on Moisture and Sweetness.
• Click "Storage" in the regression dialog and check "Fits" to store the fitted (predicted) values.
• To create a scatterplot of the data with points marked by Sweetness and two lines representing the fitted regression equation for each group:
  • Select Calc > Calculator, type "FITS_2" in the "Store result in variable" box, and type "IF('Sweetness'=2,'FITS')" in the "Expression" box. Repeat for FITS_4 (Sweetness=4).
  • Create a basic scatter plot but select "With Groups" instead of "Simple." Select Rating as the "Y variable," Moisture as the "X variable," and Sweetness as the "Categorical variable for grouping."
  • Select Editor > Add > Calculated Line and select "FITS_2" to go in the "Y column" and "Moisture" to go in the "X column." Repeat for FITS_4 (Sweetness=4).
• Perform a linear regression analysis of Rating on Moisture.
• Perform a linear regression analysis of Rating on Sweetness.

Female stat students

• Create a simple matrix of scatter plots.
• Perform a linear regression analysis of Height on momheight and dadheight.
• Create residual plots and select "Residuals versus fits" (with regular residuals).

Hospital infections

• Perform a linear regression analysis of InfctRsk on Stay, Age, and Xray.

Physiological measurements (using matrices)

• Perform a linear regression analysis of BodyFat on Triceps, Thigh, and Midarm.
• Click "Storage" in the regression dialog and check "Design matrix" to store the design matrix, X.
• To create X^T: Select Calc > Matrices > Transpose, select "XMAT" to go in the "Transpose from" box, and type "M2" in the "Store result in" box.
• To calculate X^TX: Select Calc > Matrices > Arithmetic, click "Multiply," select "M2" to go in the left-hand box, select "XMAT" to go in the right-hand box, and type "M3" in the "Store result in" box. Display the result by selecting Data > Display Data.
• To calculate (X^TX)^-1: Select Calc > Matrices > Invert, select "M3" to go in the "Invert from" box, and type "M4" in the "Store result in" box. Display the result by selecting Data > Display Data.

Peruvian blood pressure

• Use Calc > Calculator to calculate FracLife variable.
• Perform a linear regression analysis of Systol on nine predictors.
• Perform a linear regression analysis of Systol on four predictors.
• Find an F-based P-value.

Measurements of college students

• Perform a linear regression analysis of Height on LeftArm, LeftFoot, HeadCirc, and nose.
• Create residual plots and select "Residuals versus fits" (with regular residuals).
• Perform a linear regression analysis of Height on LeftArm and LeftFoot.
• Find an F-based P-value.
• Perform a linear regression analysis of Height on LeftFoot.