Breastfed vs. Not Breastfed and GCI: A researcher studied whether and how children who were breastfed during infancy differed from those who weren't. Followed up at age of 4 and measured The General Cognitive Index (GCI) which is the overall present level of intellectual functioning. The following figure summarizes the differences between the two groups.

O Show overall Show Shuffle Options: Total Shuffles = 1000 Sample data: (Explanatory, Response) O Unstacked Number of Shuffles: 1000 Mean = 0.025 Hypothesized H2-H1: 0 SD - 1.555 110. 315 Breastfed Shuffle Responses O Data O Plot NotB 104 . 489 NotBreastfed Most Recent Shuffle 106.394 Feeding Count 20 40 60 80 100 120 Breastfed 97.252 Breastfed Brea Brea NotB Feeding 96. 419 Use Data Clear 60 90 -6 120 -3 Explanatory Variable: 150 0 3 Feeding GCI 60 90 120 150 Shuffled Differences in Means GCI Response Variable: Boxplots GCI Show Original Colors Summary Statistics: Shuffled Summary Statistics: Count Samples Greater Than 2 Count Mean SD Mean SD NotB 109 102 . 40 12. 84 NotB 109 105.08 13.83 Brea 391 105.38 14.51 Brea 391 104.63 14. 32 overall 500 104.73 14.20 overall 500 104.73 14.20 Statistic: Difference in means Observed diff=2.976 Shuffled diff=-0.45