A common symptom of otitis-media (inflamation of the middle ear) in young children is the prolonged presence of fluid in the middle ear, called middle-ear effusion. It is hypothesized that breast-fed babies tend to have less prolonged effusions than do bottle-fed babies. Rosner (2006) presents the results of a study of 24 pairs of infants who were matched according to sex, socioeconomic status, and type of medication taken. One member of each pair was bottle-fed and the other was breast-fed. The file ears gives the durations (in days) of middle-ear effusions after the first episode of otitis-media. a. Examine the data using graphical methods and summarize your conclusions. b. In order to test the hypothesis of no difference, do you think it is more appropriate to use a parametric or a nonparametric test? Carry out a test. What do you conclude?
ST 512 Week Four Notes MaLyn Lawhorn September 6, 2017 Hypothesis Testing for p: All hypothesis tests pertaining to a proportion p deal with random variables of the form ▯ Y = 1; success i 0; failure where Y1;▯▯▯ ;n are independent identically distributed random variables from a binomial distri- bution. When performing hypothesis tests for proportions, using ▯ as a means to decide to reject the null hypothesis or not always a good method to use because ▯ is not easily calculated do the ”largeness” of n. Because ▯ is hard to define, so are the confidence intervals. For this reason, the best method is
