Testing a Claim about a Difference between Proportions assignment

80 printers randomly allocated evenly to 2 treatments: regular paper and cardstock paper.5 of the 40 printers using regular paper jam.15 of the 40 printers using cardstock paper jam. H0: = 0 versus Ha: < 0where pR = the proportion of all printers that jam while printing 2-sided on regular paper, and pC = the proportion of all printers that jam while printing 2-sided on cardstock paper. Use . What is the value of the standardized test statistic and P-value of this test? If needed, use the z-table to answer the question. Record the test statistic to 2 decimal places.

-2.58 0.0049

A study selected independent random samples of 50 dogs and 60 cats and found that 38 of the dogs and 15 of the cats could be trained to fetch a ball. Do these data provide convincing evidence that the proportion of all dogs that can be trained to fetch a ball is greater than the proportion of all cats that can be trained to fetch a ball? Use = 0.05. Select all statements that are correct.

A. We have two independent random samples. C. The 10% condition is met. F. The expected number of successes and failures for both samples are 24, 26, 29, 31.

80 printers randomly allocated evenly to 2 treatments: regular paper and cardstock paper.5 of the 40 printers using regular paper jam.15 of the 40 printers using cardstock paper jam. H0: = 0 versus Ha: < 0where pR = the proportion of all printers that jam while printing 2-sided on regular paper and pC = the proportion of all printers that jam while printing 2-sided on cardstock paper. Use . Select all statements that are correct.

A. We want to carry out a 2-proportion z-test. C. nR = 40 E. p = 0.25

A study selected independent random samples of 50 dogs and 60 cats and found that 38 of the dogs and 15 of the cats could be trained to fetch a ball. Do these data provide convincing evidence that the proportion of all dogs that can be trained to fetch a ball is greater than the proportion of all cats that can be trained to fetch a ball? Use . Select all statements that are correct

A. We want to carry out a 2-proportion z-test. D. nD = 50 E. p = 0.48

An analyst in the department of research and development is trying to better understand what factors cause a printer to jam when completing 2-sided printing. He has 80 printers that he randomly allocates evenly to 2 treatments: regular paper and cardstock paper. He sends a 20-page, 2-sided document to each printer and finds that 5 of the 40 printers using regular paper jam, and 15 of the 40 printers using cardstock paper jam. Do these data provide convincing evidence that the proportion of printers that would jam while printing 2-sided on regular paper is less than the proportion that would jam while printing 2-sided on cardstock? Use . Select all statements that are correct.

B. We have two groups in a randomized comparative experiment. C. The 10% condition does not apply. E. The expected number of successes and failures for both samples are 10, 30, 10, 30.

A study selected independent random samples of 50 dogs and 60 cats and found that 38 of the dogs and 15 of the cats could be trained to fetch a ball. Do these data provide convincing evidence that the proportion of all dogs that can be trained to fetch a ball is greater than the proportion of all cats that can be trained to fetch a ball? Use . Which of the following are the correct hypotheses for this test?

C. H0: = 0 versus Ha: > 0 where pD = the proportion of all dogs that can be trained to fetch a ball and pC = the proportion of all cats that can be trained to fetch a ball.

A study selected independent random samples of 50 teachers and 80 school bus drivers and found that 48% of the teachers have second jobs in the summer and 65% of the school bus drivers have second jobs in the summer. Do these data provide convincing evidence that the proportion of all teachers who have a second job in the summer is less than the proportion of all school bus drivers who have a second job in the summer? Use . What is the value of the standardized test statistic, P-value, and conclusion for this test? If needed, use the z-table to answer the question.

D. z = -1.92, P-value = 0.028, reject H0.

A trainer of police dogs wants to study the proportion of dogs that obey the "stay" command under 2 conditions: when tempted with a treat, and when distracted by a ball. The trainer has 42 dogs to use in this study. He randomly assigns half of them to be tempted to disobey the "stay" command with a treat, and the other half to be tempted to disobey the "stay" command when distracted by a ball. Of the 21 dogs that are presented with a treat, 12 still obeyed the command to stay. Of the 21 dogs that were distracted by a ball, 10 obeyed the command to stay. Do these data provide convincing evidence that the proportion of all dogs under this trainer's care that would obey the command to stay, despite distraction by a treat, differs from the proportion that would still obey when distracted by a ball? Use . What is the value of the standardized test statistic, P-value, and conclusion for this test? If needed, use the z-table to answer the question.

D. z = 0.62, P-value = 0.54, fail to reject H0.

A study selected independent random samples of 50 dogs and 60 cats and found that 38 of the dogs and 15 of the cats could be trained to fetch a ball. Do these data provide convincing evidence that the proportion of all dogs that can be trained to fetch a ball is greater than the proportion of all cats that can be trained to fetch a ball? Use . Calculate the test statistic and P-value for this test, and then complete this concluding statement.

approximately 0 less than reject have greater than

An analyst in the department of research and development is trying to better understand what factors cause a printer to jam when completing 2-sided printing. He has 80 printers that he randomly allocates evenly to 2 treatments: regular paper and cardstock paper. He sends a 20-page 2-sided document to each printer and finds that 5 of the 40 printers using regular paper jam and 15 of the 40 printers using cardstock paper jam. Do these data provide convincing evidence that the proportion of printers that would jam while printing 2-sided on regular paper is less than the proportion that would jam while printing 2-sided on cardstock? Use . Complete the statement of the hypotheses and define the population parameters for this test

equals zero is less than zero proportion proportion

80 printers randomly allocated evenly to 2 treatments: regular paper and cardstock paper.5 of the 40 printers using regular paper jam.15 of the 40 printers using cardstock paper jam. H0: = 0 versus Ha: < 0where pR = the proportion of all printers that jam while printing 2-sided on regular paper, and pC = the proportion of all printers that jam while printing 2-sided on cardstock paper. Use = 0.05. For this test, z = -2.58 and the P-value = 0.0049. What is the correct conclusion?

is less than reject have is less than