Reference no: EM132690214

Question 1: An investigator hypothesizes that cholesterol levels in children might be affected by educating their parents on proper nutrition and exercise. A sample of 40 fami-lies with a child between the ages of 10 to 15 who has been diagnosed with high cholesterol agrees to partici-pate in the study. All parents arc provided educational information on nutrition and exercise. After following the prescribed program, their child's total cholesterol level is measured. The childrens' mean cholesterol level is 175 with a standard deviation of 19.5. Is there significant evidence of a reduction in total cholesterol in the CJA clinical trial is conducted comparing a new pain reliever for arthritis to a placebo. Participants are randomly assigned to receive the new treatment or a placebo and the outcome is pain relief within 30 minutes. The data are shown in Table 7-54. Is there a significant difference in the proportions of patients reporting pain relief? Run the test at a 5% level of significance.

Question 2: A clinical trial is planned to compare an experimental medication designed to lower blood pressure to a placebo. Before starting the trial, a pilot study is conducted involving seven participants. The objective of the study is to assess how systolic blood pressures change over time if left untreated. Systolic blood pressures arc measured at baseline and again 4 weeks later. Is there a statistically significant difference in blood pressures over time? Run the test at a 5% level of significance.

Baseline: 120 145 130 160 152 143 126
4 Weeks: 122 142 135 158 155 140 130

Question 3: The The main trial in Problem 7 is conducted and in-volves a total of 200 patients. Patients are enrolled and randomized to receive either the experimental medication or the placebo. The data shown in Table 7-55 are collected at the end of the study after 6 weeks on the assigned treatment.

a. Test if there is a significant difference in mean sys-tolic blood pressures between groups using a -0.05.
b. Test if there is a significant difference in the pro-portions of hypertensive patients between groups using a = 0.05.

Question 3: A clinical trial is conducted to compare an exper-imental medication to a placebo to reduce the symptoms of asthma. Two hundred participants are enrolled in the study and randomized to receive either the experimental medication or a placebo. The primary outcome is self-reported reduction of symptoms. Among 100 participants who receive the experimental medication, 38 report a reduction of symptoms as compared to 21 participants of 100 assigned to placebo. Test if there is a significant difference in the proportions of participants

Question 5: A study is conducted to compare mean cholesterol levels for individuals following a low-carbohydrate diet for at least 6 months to individuals following a conventional (low-fat, low-calorie) diet for at least 6 months. The data are summarized in Table 7-59. Test if there is a significant difference in mean cholesterol levels between the diet programs using a 5% level of significance.

Question 6: Another outcome variable in the study described in Problem 15 is hypercholesterolemia, defined as total cholesterol over 220. Among the individuals who follow the low-carbohydrate diet, 56% are hypercholesterolemic, and among the individuals who follow the conventional diet, 40% are hypercholesterolemic. Test if there is a significant difference in the proportions using a 5% level of significance.

Attachment:- investigator hypothesizes.rar