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Verifying requirements in the largest clinical trial ever conducted, 401,974 children were randomly assigned to two groups. The treatment group considered of 201,229 children given the sulk vaccine for polio, and 33 of those children developed polio. The other 200,745 children were given a placebo, and 115 of those children developed polio. If we want to use the methods of this section to test the claim that the rate of polio is less for children given the sulk vaccine, are the requirements for a hypothesis test satisfied? Explain.

Short Answer

Expert verified

Yes, the requirement of the test is satisfied.

Step by step solution

01

Step-1: Given information

The study is conducted on 401974 children divided into two groups:

Treatment: of 201229, 33 developed polio.

Placebo: of 200,745, 115 developed polio.

02

Step-2: Express the claim

The claim to be tested is whether the rate of polio is less for children in the treatment group or not.

The test of proportions is expected to be conducted.

There are three requirements of the test.

03

Step-3: Verify the requirements

  1. Simple random samples: The samples are selected randomly
  2. Independence of group: One treatment group considered is 201,229 children given Salk vaccine for polio, and another treatment group of 200,745 children were given Placebo. These two groups are independent of each other, as there is no association between the children in each group.
  3. Counts of successes or failures: From each sample, there are at least 5 number of successes and 5 number of failures.

In the treatment group of children, the successes and failures are larger than 5. In Placebo group of children, the successes and failures are larger than 5.

Thus, requirements are satisfied.

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Most popular questions from this chapter

Testing Claims About Proportions. In Exercises 7โ€“22, test the given claim. Identify the null hypothesis, alternative hypothesis, test statistic, P-value or critical value(s), then state the conclusion about the null hypothesis, as well as the final conclusion that addresses the original claim.

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Questions Arranged from Easy to Difficult

24.64

39.29

16.32

32.83

28.02

33.31

20.60

21.13

26.69

28.9

26.43

24.23

7.10

32.86

21.06

28.89

28.71

31.73

30.02

21.96

25.49

38.81

27.85

30.29

30.72

Questions Arranged from Difficult to Easy

33.62

34.02

26.63

30.26

35.91

26.68

29.49

35.32

27.24

32.34

29.34

33.53

27.62

42.91

30.20

32.54

Determining Sample Size The sample size needed to estimate the difference between two population proportions to within a margin of error E with a confidence level of 1 - a can be found by using the following expression:

E=zฮฑ2p1q1n1+p2q2n2

Replace n1andn2 by n in the preceding formula (assuming that both samples have the same size) and replace each of role="math" localid="1649424190272" p1,q1,p2andq2by 0.5 (because their values are not known). Solving for n results in this expression:

n=zฮฑ222E2

Use this expression to find the size of each sample if you want to estimate the difference between the proportions of men and women who own smartphones. Assume that you want 95% confidence that your error is no more than 0.03.

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Females

4.4

3.4

4.8

2.9

4.4

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3.5

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Males

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3.6

4.1

4.1

3.5

4.6

4.0

4.3

4.5

4.3

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