1. Determine whether the samples are independent or dependent.
The effectiveness of a new headache medicine is tested by measuring the amount of time before the headache is cured for patients who use the medicine and another group of patients who use a placebo drug. Please explain your decision.
2. Determine whether the samples are independent or dependent.
The effectiveness of a headache medicine is tested by measuring the intensity of a headache in patients before and after drug treatment. The data consist of before and after intensities for each patient.
Please explain your decision.
3. In a random sample of 500 people aged 20-24, 22% were smokers. In a random sample of 450 people aged 25-29, 14% were smokers. Test the claim that the proportion of smokers in the two age groups is the same. Use a significance level of 0.01. (Show all steps of the hypothesis test and all calculations)
4. A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by following a particular diet. The sample data is shown below, where μ1 represents the mean blood pressure of the treatment group and μ2 represents the mean for the control group.
Use a significance level of 0.01 and whichever method you deem appropriate (p-value method, critical value method, or confidence interval method) to test the claim that the diet reduces the blood pressure. We do not know the values of the population standard deviations. Use Microsoft Excel or the following t-distribution table:
|
TREATMENT GROUP
|
CONTROL GROUP
|
|
n1
|
85
|
n2
|
75
|
| |
189.1
|
|
203.7
|
|
s1
|
38.7
|
s2
|
39.2
|