Answer needed just for 26 and 29. For each of the Exercises 24 through 34, indic
ID: 3324356 • Letter: A
Question
Answer needed just for 26 and 29.
For each of the Exercises 24 through 34, indicate whether a null hypothesis of homogeneity or a null hypothesis of independence is appropriate. 24. Aresearcher wishes to compare the status of three communities with respect to immunity against polio in preschool children. A sample of preschool children was drawn from each of the three communities In a study of the relationship between smoking and respiratory illness, a random sample of adults were classified according to consumption of tobacco and extent of respiratory symptoms 25. 26. A physician who wished to know more about the relationship between smoking and birth defects studies the health records of a sample of mothers and their children, including stillbirths and spontaneously aborted fetuses where possible. 27. A health research team believes that the incidence of depression is higher among people with hypoglycemia than among people who do not suffer from this condition. 28. In a simple random sample of 200 patients undergoing therapy at a drug abuse treatment center, 60 percent belonged to ethnic group I. The remainder belonged to ethnic group II. In ethnic group 1 60 were being treated for alcohol abuse (A), 25 for marijuana abuse (B), and 20 for abuse of heroin, illegal methadone, or some other opioid (C). The remainder had abused barbiturates, cocaine, amphetamines, hallucinogens, or some other nonopioid besides marijuana (D). In ethnic group II the abused drug category and the numbers involved were as follows: A(28) B(32) C(13) D (the remainder) Can one conclude from these data that there is a relationship between ethnic group and choice of drug to abuse? Let .05 and find the p value. 29. Solar keratoses are skin lesions commonly found on the scalp, face, backs of hands, forearms, ears scalp, and neck. They are caused by long-term sun exposure, but they are not skin cancers. Chen et al (A-24) studied 39 subjects randomly assigned (with a 3 to 1 ratio) to imiquimod cream and a control cream. The criterion for effectiveness was having 75 percent or more of the lesion area cleared after 14 weeks of treatment. There were 21 successes among 29 imiquimod-treated subjects and three successes among 10 subjects using the control cream. The researchers used Fisher's exact test and obtained a p value of .027. What are the variables involved? Are the variables quantitative or qualitative? What null and alternative hypotheses are appropriate? What are your conclusions?Explanation / Answer
Solution26:
Null Hypothesis:
H0:Smoking and birt defects are independent.
Alternative Hypothesis:
H1:Smoking and birth defects are dependent.
set alpha=0.05
conduct chi sq test for independence
Obtain a p value
if p<0.05 reject null hypothesis and conclude that smoking and bth defects are dependent.