The researchers in Exercise 14.40 also measured several other developmental milestones and their relationship to the infant's predominant sleep position.14 The results of their research are presented in the table for the 320 infants at their 4-month checkup.

Use your knowledge of the analysis of categorical data to explain the experimental design(s) used by the researchers. What hypotheses were of interest to the researchers, and what statistical test would the researchers have used? Explain the conclusions that can be drawn from the three p-values in the last column of the table and the practical implications that can be drawn from the statistical results. Have any statistical assumptions been violated?

Transcribed Image Text:

Milestone Pulls to sit with no head lag Grasps Rattle Reaches for Object Score Prone Supine or Side P Pass Fail Pass 102 Fail 3 Pass 107 Fail 3 79 144 20 167 <.21 1<.13 183 $.97