ALLIED MAT130 MODULE 5 check your understanding

Question Points

1. Find the number of successes x suggested by the given statement. Among 880 people selected randomly from among the eligible voters in one city, 52.3% were homeowners.

a. 458

b. 465

c. 462

d. 460

2. Determine whether the hypothesis test involves a sampling distribution of means that is a normal distribution, Student t distribution, or neither. You may use Figure 7-6 and Table 7-1 in your textbook. Claim about FICO credit scores of adults: = 678. Sample data: n = 12, = 719, s = 92. The sample data appear to come from a population with a distribution that is not normal, and is unknown.

a. Normal distribution

b. Student t distribution

c. Neither

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3. Assume that a hypothesis test of the given claim will conducted. Identify the type I or type II error for the test. A medical researcher claims that 20% of children suffer from a certain disorder. Identify the type I error for the test.

a. Fail to reject the claim that the percentage of children who suffer from the disorder is equal to 20% when that percentage is actually 20%.

b. Reject the claim that the percentage of children who suffer from the disorder is different from 20% when that percentage really is different from 20%.

c. Fail to reject the claim that the percentage of children who suffer from the disorder is equal to 20% when that percentage is actually different from 20%.

d. Reject the claim that the percentage of children who suffer from the disorder is equal to 20% when that percentage is actually 20%.

4. Assume that you plan to use a significance level of = 0.05 to test the claim that p1 = p2. Use the given sample sizes and numbers for successes to find the P-value for the hypothesis test. n1 = 200. n2 = 100. x1 = 11. x2 = 8

a. 0.0201

b. 0.1011

c. 0.0012

d. 0.4020

Hint: Chapter 9

5. Find the number of successes x suggested by the given statement. A computer manufacturer randomly selects 2280 of its computers for quality assurance and finds that 2.72% of these computers are found to be defective.

a. 67

b. 60

c. 62

d. 65

6. Assume that you plan to use a significance level of = 0.05 to test the claim that P1 = P2. Use the given sample sizes and numbers of successes to find the z test statistic for the hypothesis test. In a vote on the Clean Water bill, 44% of the 205 Democrats voted for the bill while 46% of the 230 Republicans voted for it.

a. z = -0.355

b. z = -0.418

c. z = -0.251

d. z = -0.460

7. Formulate the indicated conclusion in nontechnical terms. Be sure to address the original claim. A researcher claims that the amounts of acetaminophen in a certain brand of cold tablet have a standard deviation from the = 2.5 mg claimed by the manufacturer. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in nontechnical terms.

a. There is not sufficient evidence to support the claim that the standard deviation is different from 2.5 mg.

b. There is sufficient evidence to support the claim that the standard deviation is different from 2.5 mg.

c. There is sufficient evidence to support the claim that the standard deviation is equal to 2.5 mg.

d. There is not sufficient evidence to support the claim that the standard deviation is equal to 2.5 mg.

8. Find the P-value for the indicated hypothesis test. In a sample of 47 adults selected randomly from one town, it is found that 9 of them have been exposed to a particular strain of the flu. Find the P-value for a test of the claim that the proportion of all adults in the town that have been exposed to this strain of the flu is 8%.

a. 0.0524

b. 0.0262

c. 0.0048

d. 0.0024

Hint: Section 8-3

9. Find the P-value for the indicated hypothesis test. A manufacturer claims that fewer than 6% of its fax machines are defective. In a random sample of 97 such fax machines, 5% are defective. Find the P-value for a test of the manufacturer's claim.

a. 0.1591

b. 0.1736

c. 0.3264

d. 0.3409

10. Determine whether the samples are independent or dependent if possible. To test the effectiveness of Lipitor, cholesterol levels are measured in 250 subjects before and after Lipitor treatments.

a. Dependent

b. Independent

c. Cannot be determined

11. The effect of caffeine as an ingredient is tested with a sample of regular soda and another sample with decaffeinated soda.

a. Independent samples

b. Dependent samples

12. Express the null hypothesis and the alternative hypothesis in symbolic form. Use the correct symbol (, p, ) for the indicated parameter. A researcher claims that the amounts of acetaminophen in a certain brand of cold tables have a standard deviation different from the – 3.3 mg claimed by the manufacturer.

a. H0: 3.3 mg, H1: = 3.3 mg

b. H0: < 3.3 mg, H1: > 3.3 mg

c. H0: = 3.3 mg, H1: 3.3 mg

d. H0: > 3.3 mg, H1: < 3.3 mg

13. Formulate the indicated conclusion in nontechnical terms. Be sure to address the original claim. The manufacturer of a refrigerator system for beer kegs produces refrigerators that are supposed to maintain a true mean temperature, , of 45°F, ideal for a certain type of German pilsner. The owner of the brewery does not agree with the refrigerator manufacture and claims he can prove that the true mean temperature is incorrect. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms.

a. There is not sufficient evidence to support the claim that the mean temperature is equal to 45°F.

b. There is sufficient evidence to support the claim that the mean temperature is different from 45°F.

c. There is sufficient evidence to support the claim that the mean temperature is equal to 45°F.

d. There is not sufficient evidence to support the claim that the mean temperature is different from 45°F.

14. Determine whether the hypothesis test involves a sampling distribution of means that is a normal distribution, Student t distribution, or neither. You may use Figure 7-6 and Table 7-1 in your textbook. Claim about IQ scores of statistics instructors: >100. Sample data: n = 15, = 118, s = 11. The sample data appear to come from a normally distributed population with unknown and .

a. Normal distribution

b. Student t distribution

c. Neither

15. Find the number of successes x suggested by the given statement. Among 900 people selected randomly from among the residents of one city, 18.56% were found to be living below the official poverty line.

a. 170

b. 171

c. 164

d. 167