Ten individuals went on a low–fat diet for 12 weeks to lower their cholesterol. The data are recorded in Table 10.30. Do you think that their cholesterol levels were significantly lowered?

Starting cholesterol levelEnding cholesterol level140140220230110120240220200190180150190200360300280300260240

Use the following information to answer the next two exercises. A new AIDS prevention drug was tried on a group of 224 HIV positive patients. Forty-five patients developed AIDS after four years. In a control group of 224 HIV positive patients, 68 developed AIDS after four years. We want to test whether the method of treatment reduces the proportion of patients that develop AIDS after four years or if the proportions of the treated group and the untreated group stay the same.

Let the subscript t=treated patient and ut=untreated patient.

Short Answer

Expert verified

The null and alternative hypothesis are: H0:μd=0and H0:μd<0

The test statistics is : 1.17

The value ofpis:0.865

Step by step solution

01

Given Information 

Given in the question that,

Starting cholesterol levelEnding cholesterol level140140220230110120240220200190180150190200360300280300260240

02

Explanation 

The null hypothesis is defined as follows:

H0:μd=0

The following is an alternative hypothesis:

H0:μd<0

The mean difference in cholesterol levels is the random variable.

The distribution of students.

Fill in all requirements using Minitab's two sample ttest option.

After we have entered all of the values, we will' get the following result.

The value of test statistics is: localid="1654021055728" 1.17

The value of localid="1654021065369" Pis: localid="1654021074185" 0.865

The graph of the p value is shown below:

Here, α=0.05

We can accept the null hypothesis. Because p-value<α.

There is insufficient data to determine that the drug reduced cholesterol levels after 12 weeks at the 5 percent threshold of significance.

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Most popular questions from this chapter

Use the following information to answer the next five exercises. A study was conducted to test the effectiveness of a software patch in reducing system failures over a six-month period. Results for randomly selected installations are shown in Table 10.21. The “before” value is matched to an “after” value, and the differences are calculated. The differences have a normal distribution. Test at the 1% significance level.

What conclusion can you draw about the software patch?

Use the following information to answer the next 15exercises: Indicate if the hypothesis test is for

a. independent group means, population standard deviations, and/or variances known

b. independent group means, population standard deviations, and/or variances unknown

c. matched or paired samples

d. single mean

e. two proportions

f. single proportion

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Use the following information to answer the next twelve exercises. In the recent Census, three percent of the U.S. population reported being of two or more races. However, the percent varies tremendously from state to state. Suppose that two random surveys are conducted. In the first random survey, out of 1,000 North Dakotans, only nine people reported being of two or more races. In the second random survey, out of 500 Nevadans, 17 people reported being of two or more races. Conduct a hypothesis test to determine if the population percents are the same for the two states or if the percent for Nevada is statistically higher than for North Dakota.

Explain why you chose the distribution you did for the Exercise 10.56.

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What is the p-value?

Use the following information to answer next five exercises. A study was conducted to test the effectiveness of a juggling class. Before the class started, six subjects juggled as many balls as they could at once. After the class, the same six subjects juggled as many balls as they could. The differences in the number of balls are calculated. The differences have a normal distribution. Test at the 1% significance level

What is the sample mean difference?

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