Q1. An investigator hypothesizes that cholesterol level in children might be affected by educating their parents on proper nutrition and exercise . A sample of 40 families with a child between the ages of 10 to 15 who has been diagnosed with high cholesterol agree to participate in the study. All parents are provided educational information on nutrition and exercise . After following the prescribed program, their Childs total cholesterol level is measured. The children mean cholesterol level is 175 with standard deviation of 19.5. Is there significance evidence of a reduction in total cholesterol level in the children ? Run the appropriate test at the 5% level of significance and assume that the null value for total cholesterol is 191
Q2. 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 change over time if left untreated .Systolic blood pressure are measured at baseline and again in 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
Week 4 : 122 142 135 158 155 140 130
Q3. The main trial in problem 2 is conducted and involves a total of 200 patients. Patients are enrolled and randomized to receive either the experimental medication or the placebo. The data shown below are collected at the end of the study after 6 weeks on assigned treatment.
a) Test if there is a significant difference in mean systolic blood pressure between groups using = 0.05.
b) Test if there is a significance difference in the proportions of hypertensive patients between groups using =0.05
Pain Relief Treatment:
Pain relief No pain Relief
New Medication 44 76
Placebo 21 99
Q4. Recent Recommendation suggest 60 minutes of Physical activity per day. A sample of 50 adults in a study of cardiovascular risk factors reports exercising a mean of 38 minutes per day with standard deviation of 19 minutes . Based on a sample data, is the physical activity significantly less than recommended? Run the appropriate test at 5% level of significance.