A nurse investigates the consequences of premature delivery on later personality development. He predicts that premature babies will be orally dependent. He examines City Lane Hospital’s records and...

A nurse investigates the consequences of premature delivery on later personality development. He predicts that premature babies will be orally dependent. He examines City Lane Hospital’s records and randomly draws three groups of participants: a group delivered before the seventh month of the mother’s pregnancy, a group delivered between seven and eight-and-a-half months of pregnancy, and a group delivered after eight-and-a-half months of pregnancy. The nurse contacts each participant’s mother and asks her to indicate how old the child was (in weeks) when she stopped breastfeeding. The data are as follows:

Is the nurse’s theoretical hunch supported by the data? Analyse the data comprehensively: for example, run multiple comparisons if necessary, and calculate magnitude of effect size to see how substantial the differences between the groups are.