Module 4 Homework Assignment

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. Explain.

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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. Explain.

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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.

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4. A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by following a particular diet. Use the sample data below to perform all steps for hypothesis testing or construct a 99% confidence interval for µ1 – µ2 where µ 1 and µ2 represent the mean for the treatment group and the control group respectively. Use the following t-distribution table – http://www.itl.nist.gov/div898/handbook/eda/section3/eda3672.htm

Treatment Group Control Group

n1 = 85 n2 = 75

189.1 = 203.7

s1 = 38.7 s2 = 39.2

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For questions 5 – 9 below, use the traditional method of hypothesis testing to test the given claim about the means of two populations. Assume that two dependent samples have been randomly selected from normally distributed populations.

Five students took a math test before and after tutoring. Their scores were as follows.

Student

A

B

C

D

E

Before

71

66

67

77

75

After

75

75

65

80

87

Using a 0.01 level of significance, test the claim that the tutoring has an effect on the math scores.

5. State the null and alternative hypotheses.

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6. Find d, , and sd,

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7. Find the value of the test statistic, t.

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8. Find the critical value(s) and state the decision about the null hypothesis.

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9. State the conclusion in non-technical terms.

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