Chapter 23-25 Multiple Choice Exam Review
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Chapter 24 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Construct the indicated confidence interval for the difference between the two population means. Assume that the assumptions and conditions for inference have been met. 1) 120 Brand X oil filters and 90 Brand Y oil filters were tested for milligrams of residue, with the 1) following results. Find a 95% confidence interval for µY - µX .
A = 5.9 B = 0.87 C = 4.7 D = 0.86 A) (-1.84, -0.56) B) (0.96, 1.44) C) (0.92, 1.48) D) (-1.44, -0.96) E) (0.92, -0.96)
Interpret the given confidence interval. 2) A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure by following a particular diet. Subjects were randomly assigned to a treatment group and a control group. The mean blood pressure was determined for each group, and a 98% confidence interval for the difference in the mean for the treatment group and the control group, µt - µc, was found to be (-27, -4). A) With 98% confidence, people who follow the diet have an average blood pressure between 4 and 27 points lower than people who do not follow the diet. B) We know that 98% of all people who follow the particular diet will have a blood pressure between 4 and 27 points lower than people who do not follow the diet. C) We are 98% confident that a randomly selected subject in the treatment group had a blood pressure between 4 and 27 points lower than a randomly selected subject in the control group. D) With 98% confidence, people who follow the diet have an average blood pressure between 4 and 27 points higher than people who do not follow the diet. E) We know that 98% of all experiments done on the population will show that the average blood pressure for people who follow the diet is between 4 and 27 points lower than the average blood pressure for people who do not follow the diet.
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SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Assume that the assumptions and conditions for inference with a two-sample t-test are met. Test the indicated claim about the means of the two populations. 3) The Better Cookie Company claims its chocolate chip cookies have more chips than 3) another chocolate chip cookie. 120 Better Cookies and 100 of the other type of cookie were randomly selected and the number of chips in each cookie was recorded. The results are as follows.
Mean number of chips Standard deviation
Better 7.6 1.4
Another 6.9 1.7
At the 2% level of significance, test the claim that the population of Better Cookies has a higher mean number of chips.
Use the computer display to answer the question. 4) When testing for a difference between the means of a treatment group and a placebo group, the computer display below is obtained. Using a 0.05 significance level, is there sufficient evidence to support the claim that the treatment group (variable 1) comes from a population with a mean that is different from the mean for the placebo population? Explain.
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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Provide an appropriate response. 5) A researcher is interested in the academic performance differences between individuals using an optimistic versus a pessimistic approach to their studies. If the researcher fails to find a significant difference, when in fact one exists in the population: A) the null hypothesis was correctly rejected. B) the research hypothesis was correctly accepted. C) the null hypothesis was correctly accepted. D) a Type 1 error has been made. E) a Type 2 error has been made.
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6) A researcher is interested in the academic performance differences between individuals using an optimistic versus a pessimistic approach to their studies. If the researcher claims a significant difference between groups, when in fact none exists: A) a Type 1 error is made. B) the null hypothesis was correctly accepted. C) a Type 2 error is made. D) the research hypothesis was correctly rejected. E) the research hypothesis was correctly accepted.
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7) When we accept the null hypothesis, we A) have committed a Type II error. B) have obtained a t-value greater than our critical t-value. C) claim that a significant difference exists between groups. D) conclude that sampling error is responsible for our obtained difference. E) have committed a Type I error.
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8) A philosophy professor wants to find out whether the mean age of the men in his large lecture class is equal to the mean age of the women in his classes. After collecting data from a random sample of his students, the professor tested the hypothesis H0 : µm - µw = 0 against the alternative
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HA: µm - µw
0. The P-value for the test was 0.003. Which is true?
A) There is a 0.3% chance that the mean ages for the men and women are equal. B) There is a 99.7% chance that another sample will give these same results. C) It is very unlikely that the professor would see results like these if the mean age of men was equal to the mean age of women. D) There is a 0.3% chance that another sample will give these same results. E) There is a 0.3% chance that the mean ages for the men and women are different.
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Answer Key Testname: CH 24 MC FRQ REVIEW 2016
1) D 2) A 3) H0 : µ1 - µ2 = 0
4) 5) 6) 7) 8)
HA: µ1 - µ2 > 0
Test statistic t = 3.291, P-value = 5.94 × 10-4 , DF = 191.61 Reject the null hypothesis. There is sufficient evidence to support the claim that the population of Better Cookies has a higher mean number of chips. No, the P-value for a two-tail test is 0.0768, which is greater than the significance level of 0.05. There is not sufficient evidence to support the claim that the two population means are different. E A D C
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