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Statistics exam 40 questions

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Question;Question 3 of 40 0.0/ 2.5;Points;A two-tailed test is;conducted at the 5% significance level. Which of the z-scores below is the;smallest one that leads to rejection of the null hypothesis?;A. 1.12;B. 1.48;C. 1.84;D. 2.15;Question 4 of 40 0.0/ 2.5;Points;A psychologist claims that;more than 19 percent of the population suffers from professional problems due;to extreme shyness. Assume that a hypothesis test of the claim has been;conducted and that the conclusion of the test was to reject the null hypothesis.;Identify the population to which the results of the test apply.;A. The population is all shy;workers.;B. The population cannot be;identified from the description of the study.;C. The population is all;American workers.;D. The population is all;American professional workers (doctors, lawyers, CPA?s, and the like..;Question 5 of 40 0.0/ 2.5;Points;A researcher claims that the;amounts of acetaminophen in a certain brand of cold tablets have a mean;different from the 600 mg claimed by the manufacturer. Test this claim at the;0.02 level of significance. The mean acetaminophen content for a random sample;of n = 41 tablets is 603.3 mg. Assume that the population standard deviation is;4.9 mg.;A. Since the test statistic;is greater than the critical z, there is sufficient evidence to accept the null;hypothesis and to support the claim that the mean content of acetaminophen is;600 mg.;B. Since the test statistic;is greater than the critical z, there is sufficient evidence to reject the null;hypothesis and to support the claim that the mean content of acetaminophen is;not 600 mg.;C. Since the test statistic;is less than the critical z, there is sufficient evidence to reject the null;hypothesis and to support the claim that the mean content of acetaminophen is;not 600 mg.;D. Since the test statistic;is greater than the critical z, there is insufficient evidence to reject the;null hypothesis and to support the claim that the mean content of acetaminophen;is not 600 mg.;Question 6 of 40 0.0/ 2.5;Points;z = 1.8 for Ha: ? >?claimed;value. What is the P-value for the test?;A. 0.9641;B. 3.59;C. 96.41;D. 0.0359;Question 7 of 40 0.0/ 2.5;Points;In 1990, the average;duration of long-distance telephone calls originating in one town was 9.4;minutes. A long-distance telephone company wants to perform a hypothesis test;to determine whether the average duration of long-distance phone calls has;changed from the 1990 mean of 9.4 minutes. The mean duration for a random;sample of 50 calls originating in the town was 8.6 minutes. Does the data;provide sufficient evidence to conclude that the mean call duration, ?, is;different from the 1990 mean of 9.4 minutes? Perform the appropriate hypothesis;test using a significance level of 0.01. Assume that;1.2 there is sufficient;evidence to conclude that the mean value has changed from the 1990 mean of 9.4;minutes.?A. With a z of;B. With a P-value of 0.2302;there is not sufficient evidence to conclude that the mean value is less than;the 1990 mean of 9.4 minutes.;C. With a P-value of 0.2302;there is sufficient evidence to conclude that the mean value is less than the;1990 mean of 9.4 minutes.;D. With a z of ?1.2 there is;not sufficient evidence to conclude that the mean value has changed from the;1990 mean of 9.4 minutes.;Question 9 of 40 0.0/ 2.5;Points;A right-tailed test is;conducted at the 5% significance level. Which of the following z-scores is the;smallest one in absolute value that leads to rejection of the null hypothesis?;A. 1.61;B. 1.85;C. -1.98;D. -2.06;Question 11 of 40 0.0/ 2.5 Points;A consumer group claims that;the mean running time for a certain type of flashlight battery is not the same;as the manufacturer?s claims. Determine the null and alternative hypotheses for;the test described.;A.;H0: ? = Manufacturer?s;claims Ha: ? Manufacturer?s claims;D.;H0: ?? Manufacturer?s;claims Ha: ? = Manufacturer?s claims;Question 12 of 40 0.0/ 2.5;Points;A poll of 1,068 adult;Americans reveals that 52% of the voters surveyed prefer the Democratic;candidate for the presidency. At the 0.05 significance level, test the claim;that more than half of all voters prefer the Democrat.;A. Reject the null;hypothesis. Conclude that there is insufficient evidence that more than half of;all voters prefer Democrats.;B. Do not reject the null;hypothesis. Conclude that there is sufficient evidence that more than half of;all voters prefer Democrats.;C. Reject the null;hypothesis. Conclude that there is sufficient evidence that more than half of;all voters prefer Democrats.;D. Do not reject the null;hypothesis. Conclude that there is insufficient evidence that more than half of;all voters prefer Democrat;Question 13 of 40 0.0/ 2.5;Points;A long-distance telephone;company claims that the mean duration of long-distance telephone calls;originating in one town was greater than 9.4 minutes, which is the average for;the state. Determine the conclusion of the hypothesis test assuming that the;results of the sampling do not lead to rejection of the null hypothesis.;A. Conclusion: Support the;claim that the mean is less than 9.4 minutes.;B. Conclusion: Support the;claim that the mean is greater than 9.4 minutes.;C. Conclusion: Support the;claim that the mean is equal to 9.4 minutes.;D. Conclusion: Do not;support the claim that the mean is greater than 9.4 minutes.;Question 14 of 40 0.0/ 2.5;Points;The owner of a football team;claims that the average attendance at home games is over 4000, and he is;therefore justified in moving the team to a city with a larger stadium. Assume;that a hypothesis test of the claim has been conducted and that the conclusion;of the test was to reject the null hypothesis. Identify the population to which;the results of the test apply.;A. All games played by the;team in question in which the attendance is over 4000;B. All future home games to;be played by the team in question;C. All home games played by;the team in question;D. None of the populations;given are appropriate;Question 15 of 40 0.0/ 2.5;Points;A psychologist claims that;more than 29 percent of the professional population suffers from problems due;to extreme shyness. 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 non-technical terms.;A. There is sufficient;evidence to support the claim that the true proportion is less than 29 percent.;B. There is not sufficient;evidence to support the claim that the true proportion is greater than 29;percent.;C. There is sufficient;evidence to support the claim that the true proportion is equal to 29 percent.;D. There is sufficient;evidence to support the claim that the true proportion is greater than 29;percent.;Question 17 of 40 0.0/ 2.5;Points;If a fan purchased a bag;with 30 peanuts, what is the lowest level at which this would be a significant;event?;A. 0.05;B. 0.025;C. 0.01;D. It is not significant at;any of the levels given;Question 18 of 40 0.0/ 2.5;Points;In the past, the mean;running time for a certain type of flashlight battery has been 8.0 hours. The;manufacturer has introduced a change in the production method and wants to;perform a hypothesis test to determine whether the mean running time has;increased as a result. The hypotheses are;H0: ? = 8.0 hours;Ha: ? > 8.0 hours;Explain the meaning of a;Type II error.;A. Concluding that ? >;8.0 hours when in fact ? > 8.0 hours;B. Failing to reject the;hypothesis that ? = 8.0 hours when in fact ? >;8.0 hours;C. Concluding that ? >;8.0 hours;D. Failing to reject the;hypothesis that ? = 8.0 hours when in fact ? = 8.0 hours;Question 20 of 40 0.0/ 2.5;Points;At one school, the mean;amount of time that tenth-graders spend watching television each week is 18.4;hours. The principal introduces a campaign to encourage the students to watch;less television. One year later, the principal wants to perform a hypothesis;test to determine whether the average amount of time spent watching television;per week has decreased.;Formulate the null and;alternative hypotheses for the study described.;A.Ho: ? = 18.4 hours H?: ?;? 18.4 hours;B.Ho: ? = 18.4 hours H?: ?;170, Ha: ? =;170;B.H0: ?;170;D.H0: ? = 160, Ha: ? >;160Part 2 of 2 ?;Question 27 of 40 0.0/ 2.5;Points;One hundred people are;selected at random and tested for colorblindness to determine whether gender;and colorblindness are independent. The following counts were observed.;Colorblind Not Colorblind;Total;Male 8 52 60;Female 2 38 40;Total 10 90 100;Find the value of the?2;statistic for the data above.;A. 1.463;B. 1.852;C. 1.947;D. 1.949Question 29 of 40;0.0/ 2.5 Points;Which of the following;statements is true?;A. The p distribution cannot;be used when finding a confidence interval for the population mean with a small;sample anytime the population standard deviation is unknown.;B. The t distribution can be;used when finding a confidence interval for the population mean with a small;sample anytime the population standard deviation is unknown.;C. The t distribution cannot;be used when finding a confidence interval for the population mean with a small;sample anytime the population standard deviation is unknown.;D. The p distribution can be;used when finding a confidence interval for the population mean with a small;sample anytime the population standard deviation is unknown.Question 30 of 40;0.0/ 2.5 Points;Which of the following;statements is true?;A. The t distribution cannot;be used when finding a confidence interval for the population mean with a small;sample whenever the sample comes from a symmetric population.;B. The t distribution can be;used when finding a confidence interval for the population mean with a small;sample whenever the sample comes from a symmetric population.;C. The p distribution can be;used when finding a confidence interval for the population mean with a small;sample whenever the sample comes from a symmetric population.;D. The p distribution can be;used when finding a confidence interval for the population mean with a small;sample whenever the sample comes from a symmetric population.;Question 31 of 40 0.0/ 2.5;Points;The critical value of?2 for;a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the?2;statistic in Problem 8 had been 3.427, state your conclusion about the;relationship between gender and colorblindness.;A.Do not reject H0. There is;not sufficient evidence to support the claim that gender and colorblindness are;related.;B.Do not reject H0. There is;sufficient evidence to support the claim that gender and colorblindness are;related.;C.Reject H0. There is not;sufficient evidence to support the claim that gender and colorblindness are;related.;D.Reject H0. There is;sufficient evidence to support the claim that gender and colorblindness are;related.;Question 32 of 40 2.5/ 2.5;Points;The following data were;analyzed using one-way analysis of variance.;A B C;34 27 19;26 23 31;31 29 22;28 21 22;Which one of the following;statements is correct?;A.The purpose of the;analysis is to determine whether the groups A, B, and C are independent.;B. The purpose of the;analysis is to test the hypothesis that the population means of the three;groups are equal.;C. The purpose of the;analysis is to test the hypothesis that the population variances of the three;groups are equal.;D. The purpose of the;analysis is to test the hypothesis that the sample means of the three groups;are equal.;Question 33 of 40 0.0/ 2.5;Points;The __________ test statistic;is for the one-way analysis of variance.;A. P-Value;B. t;C. F;D. p;Question 34 of 40 0.0/ 2.5;Points;One hundred people are;selected at random and tested for colorblindness to determine whether gender;and colorblindness are independent. The following counts were observed.;Colorblind Not Colorblind;Total;Male 7 53 60;Female 1 39 40;Total 8 92 100;If gender and colorblindness;are independent, find the expected values corresponding to the female combination;Question 39 of 40 0.0/ 2.5;Points;The scatter plot and;best-fit line show the relation among the data for the price of a stock (y) and;employment (x) in arbitrary units. The correlation coefficient is 0.8. Predict;the stock price for an employment value of 6.;A. 8.8;B. 6.2;C. 8.2;D. None of the values are;correct;Question 40 of 40 0.0/ 2.5;Points;Which graph has two groups;of data, correlations within each group, but no correlation among all the data?;A.;B.;C.;D.The End!!

 

Paper#60215 | Written in 18-Jul-2015

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