Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 12.9 minutes. The standard deviation of completion times was 1.8 minutes. An analyst at the company suspects that, under new management, the mean completion time, µ, is now less than 12.9 minutes. To test this claim, a random sample of 80 completion times under new management was taken by the analyst. The sample had a mean of 12.7 minutes. Can we support, at the 0.10 level of significance, the claim that the population mean completion time under new management is less than 12.9 minutes? Assume that the population standard deviation of completion times has not changed under new management. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H,. H, : u = 12.9 Η , : μ 12.9 (b) Determine the type of test statistic to use. OSO (c) Find the value of the test statistic. (Round to three or more decimal places.) 0.99 (d) Find the p-value. (Round to three or more decimal places.) (e) Can we support the claim that the population mean completion time under new management is less than 12.9 minutes? OYes ONo

It takes an average of 10.2 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will decline if the patient is immediately told the truth about the injury. The EMT randomly selected 60 injured patients to immediately tell the truth about the injury and noticed that they averaged 10.1 minutes for their blood to begin clotting after their injury. Their standard deviation was 1.62 minutes. What can be concluded at the the a = 0.01 level of significance? a. For this study, we should use Select an answer b. The null and altemative hypotheses would be: Họ: Select an answer H1: ? Select an answer c. The test statistic (please show your answer to 3 decimal places.) d. The p-value = e. The p-value is (? va f. Based on this, we should Select an answer v the null hypothesis. g. Thus, the final conclusion is that .. (Please show your answer to 4 decimal places.) O The data suggest the population mean is not significantly less than 10.2 at a = 0.01, so there is…

Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 13.3 minutes. The standard deviation of completion times was 1.8 minutes. An analyst at the company suspects that, under new management, the mean completion time, μ, is now less than 13.3 minutes. To test this claim, a random sample of 80 completion times under new management was taken by the analyst. The sample had a mean of 12.8 minutes. Can we support, at the 0.01 level of significance, the claim that the population mean completion time under new management is less than 13.3 minutes? Assume that the population standard deviation of completion times has not changed under new management. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. A. Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an…

A random sample of 100 observations from a quantitative population produced a sample mean of 28.0 and a sample standard deviation of 6.5. Use the p-value approach to determine whether the population mean is different from 31.

In Professor Krugman’s economics course, the correlation between the students’ total scores prior to the final examination and their final‑examination scores is ?=0.5.r=0.5. The pre‑exam totals for all students in the course have mean 280280 and standard deviation 40.40. The final‑exam scores have mean 7575 and standard deviation 8.8. Professor Krugman has lost Julie’s final exam but knows that her total before the exam was 300.300. He decides to predict her final‑exam score from her pre‑exam total. (a) Which of the choices is the least‑squares regression line of final‑exam scores on pre‑exam total scores in this course?

In Professor Krugman's economics course, the correlation between the students' total scores prior to the final examination and their final‑examination scores is ?=0.5.�=0.5. The pre‑exam totals for all students in the course have mean 280280 and standard deviation 40.40. The final‑exam scores have mean 7575 and standard deviation 8.8. Professor Krugman has lost Julie's final exam but knows that her total before the exam was 300.300. He decides to predict her final‑exam score from her pre‑exam total.   © Macmillan Learning (a) What is the slope of the least-squares regression line of final-exam scores on pre-exam total scores in this course? Give your answer to one decimal place. slope:     What is the intercept? Give your answer as a whole number. intercept:

Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 12.7 minutes. The standard deviation of completion times was 1.4 minutes. An analyst at the company suspects that, under new management, the mean completion time, μ , is now less than 12.7 minutes. To test this claim, a random sample of 80 completion times under new management was taken by the analyst. The sample had a mean of 12.6 minutes. Can we support, at the 0.05 level of significance, the claim that the population mean completion time under new management is less than 12.7 minutes? Assume that the population standard deviation of completion times has not changed under new management. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H0…

During the busy season, it is important for the shipping manager at ShipMundo to be able to estimate the time it takes the loading crew to load a truck. The shipping manager has found that she can model the load times using a normal distribution with a mean of 152 minutes and a standard deviation of 15 minutes. Use this table or the ALEKS calculator to find the percentage of load times between 116 minutes and 149 minutes according to the model. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%).