Week 5 Lab HW 5 Due on Friday of Week 6 at 5pm via Canvas and Aplia
Aplia: Ch. 12 Introduction to Analysis of Variance
SPSS (15 Points): Include relevant SPSS output. State whether your decision is to
reject or retain the null hypothesis and why. Provide an APA style summary.
First-born children tend to develop language skills faster than their younger siblings.
One possible explanation for this phenomenon is that first-borns have undivided
attention from their parents. If this explanation is correct, then it is also reasonable that
twins should show slower language development than single children and that triplets
should be even slower. Davis (1937) found exactly this result. The following data
demonstrate the relationship. The dependent variable is measure of language skill at
age 3 for each child.
Single Child
Twin
Triplet
8
6
5
7
4
5
10
6
8
6
7
3
9
4
5
8
9
4
a) Use an ANOVA with ? =.05 to determine whether there are any significant differences
among the 3 groups of children.
b) Use the Scheffe post-test to determine which groups are significantly different.
