Applying ANOVAApplying ANOVA

Using brute-force, Excel and Using brute-force, Excel and Minitab to perform ANOVAMinitab to perform ANOVA

Warm-upWarm-up

Look at the following applet from the IPS Look at the following applet from the IPS website to remind you that ANOVA and F-website to remind you that ANOVA and F-scores investigate two sets of variances:scores investigate two sets of variances:

• Variances between data setsVariances between data sets• Variances within data sets Variances within data sets

Example 12.21 Example 12.21 (pg 786)(pg 786)

Graph data – use boxplots if you have a stats Graph data – use boxplots if you have a stats packagepackage

Prepare a table giving n, Prepare a table giving n, and and for each for each groupgroup

Time Energy intake (kcal/d)

4 Months 499 620 469 485 660 588 675 517 649 209

  404 738 628 609 617 704 558 653 548  

5 months 490 395 402 177 475 617 616 587 528 518

  370 431 518 639 368 538 519 506    

6 Months 585 647 477 445 485 703 528 465    

N1 = 19

N2 = 19

N3 = 8

Boxplot of dataBoxplot of data

Are the means different?Are the means different?

Example 12.23 Example 12.23 (pg 787)(pg 787)

Group Bone Density (mg/cm3)

Control 611 621 614 593 593 653 600 554 603 569

Low Jump 635 605 638 594 599 632 631 588 607 596

High Jump 650 622 626 626 631 622 643 674 643 650