In 2015, the average duration of long-distance telephone calls from a certain town was 9.4 minutes. A telephone company wants to perform a test to determine whether this average duration of long-distance calls has changed. Twenty calls, originating from the town, was Course Name and Code –randomly selected and the mean duration was 10.2 minutes with standard deviation 4.8 minutes. a) Using a 1% level of significance, Complete the following: Give the null and alternative hypothesis of this test. ] ii. Determine the critical value(s) of this test.

A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is not equal to the mean of WaxCo. In a random sample of 12 floors of WaxWin and 20 of WaxCo. WaxWin had a mean lifetime of 27.6 with a standard deviation of 8.8 and WaxCo had a mean lifetime of 20.3 with a standard deviation of 7.6. Perform a hypothesis test using a significance level of 0.01 to help him decide. Let WaxWin be sample 1 and WaxCo be sample 2 The correct hypotheses are: HA: P1 > µ2(claim) Ho: µ1 2 µ2 HA: µ1 < µ2(claim) Ho: µ1 = µ2 HA: H1 + H2(claim) Since the level of significance is 0.01 the critical value is 2.836 and -2.836 The test statistic is: (round to 3 places) The p-value is: (round to 3 places)

Nationally, patients who go to the emergency room wait an average of 7 hours to be admitted into the hospital. Do patients at rural hospitals have a different waiting time? The 12 randomly selected patients who went to the emergency room at rural hospitals waited an average of 5.8 hours to be admitted into the hospital. The standard deviation for these 12 patients was 1.8 hours. What can be concluded at the a = 0.10 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ? Select an answer ✓ H₁: ?v Select an answer ✓ c. The test statistic ? ✓ (please show your answer to 3 decimal places.) (Please show your answer to 4 decimal places.) d. The p-value = e. The p-value is ? a f. Based on this, we should Select an answer the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest that the population mean awaiting time to be admitted into the hospital from the emergency room for…

The State Transportation Department is thinking of changing its speed limit signs. It is considering two new options in addition to the existing sign design. At question is whether the three sign designs will produce the same mean speed. To test this, the department has conducted a limited test in which a stretch of roadway was selected. With the original signs up, a random sample of 30 cars was selected and the speeds were measured. Then, on different days, the two new designs were installed, 30 cars each day were sampled, and their speeds were recorded. Suppose that the following summary statistics were computed based on the data. X₁ = 62.1 X₂ = 58.94 X3 = 71.2 SST = 6016 Based on these sample results and significance level equal to 0.05, what is the sum of squares between?

A custodian wishes to compare two competing floor waxes to decide which one is best. He believes that the mean of WaxWin is less than the mean of WaxCo. In a random sample of 20 floors of WaxWin and 17 of WaxCo. WaxWin had a mean lifetime of 26.4 with a standard deviation of 8.6 and WaxCo had a mean lifetime of 27.2 with a standard deviation of 6.6. Perform a hypothesis test using a significance level of 0.05 to help him decide. Let WaxWin be sample 1 and WaxCo be sample 2 The correct hypotheses are: Ο Ηο: μι < με HA₁₂(claim) Ο Ηρ: με 2 με HA: 1₂(claim) O Ho: ₁ = ₂ HAM12(claim) Since the level of significance is 0.05 the critical value is -1.69 (round to 3 places) The test statistic is: The p-value is: (round to 3 places)

Nationally, patients who go to the emergency room wait an average of 5 hours to be admitted into the hospital. Do patients at rural hospitals have a different waiting time? The 12 randomly selected patients who went to the emergency room at rural hospitals waited an average of 3.9 hours to be admitted into the hospital. The standard deviation for these 12 patients was 2.2 hours. What can be concluded at the the a = 0.10 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho:2 Select an answer H: Select an answer C. The test statistic ? v (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimnal places.) e. The p-value is ? Based on this, we should Select an answer the null hypothesis. 2. Thus, the final conclusion is that The data suggest the population mean is not significantly different from 5 at a = 0.10, so there is statistically insignificant…

In the past, the time for Jeff's journey to work had mean 45.7 minutes and standard deviation 5.6 minutes. This year he is trying a new route. In order to test whether the new route has reduced his journey time, Jeff finds the mean time for a random sample of 30 journeys using the new route. He camies out a hypothesis test at the 2.5% significance level. Jeff assumes that, for the new route, the joumey time has a nomal distribution with standard deviation 5.6 minutes. (a) State appropriate null and alternative hypotheses for the test. (b) Determine the rejection region for the test.

A criminologist was interested in whether there was any disparity in sentencing. She selected at random of 24 drug convictions for cocaine distribution and compared the prison terms given by two judges as below.  Judge1 Judge2 7 5 7 6 6 4 5 5 2 5 5 5 7 4 6 6 5 5 7 5 10 4 7 5 From performing a hypothesis test to determine if judge1 differs from judge2 in the mean of sentence years, what is the p-value? (Round off to three decimal places if necessary)

Suppose a recent study of Trucks and SUVs gave an average fuel efficiency of 19.2 mpg for Trucks and 21.4 mpg for SUVs. The sample standard deviation for Trucks was 3.2 mpg and 2.8 mpg for SUVs. These results were based on samples of 35 Trucks and 39 SUVs. At the 1% significance level, can we conclude that, on average, SUVs have better fuel efficiency than Trucks? Clearly state the null and alternative hypotheses, use the critical value approach (draw a detailed picture), and write out a detailed conclusion. Organize: Hypotheses: Detailed picture: Detailed conclusion:

Nationally, patients who go to the emergency room wait an average of 4 hours to be admitted into the hospital. Do patients at rural hospitals have a lower waiting time? The 13 randomly selected patients who went to the emergency room at rural hospitals waited an average of 3.2 hours to be admitted into the hospital. The standard deviation for these 13 patients was 2.9 hours. What can be concluded at the the a = 0.10 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Select an answer V Select an answer c. The test statistic ? v (please show your answer to 3 decimal places.) d. The p-value = (Please showyour answer to 4 decimal places.) e. The p-value is 7 v f. Based on this, we should Select an answer v the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest that the population mean awaiting time to be admitted into the hospital from the emergency room for patients at…