Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 14.2 min The standard deviation of completion times was 1.6 minutes. An analyst at the company suspects that, under new management, the mean completion time, µ, is now less than 14.2 minutes. To test this claim, a random sample of 12 completion times under new management was taken by the analyst. The sample had a mean of 13 minutes. Assume that the population is normally distributed. C we support, at the 0.01 level of significance, the claim that the population mean completion time under new management is less than 14.2 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 manufacturer knows that their items have a normally distributed lifespan, with a mean of 4.9 years, and standard deviation of 1.2 years.The 4% of items with the shortest lifespan will last less than how many years?Give your answer to one decimal place.

Suppose a population is known to be normally distribted with a mean, μ, equal to 116 and a standard deviation, σ,equal to 14. Approximately what percent of the population would be between 88 and 130?

The warranty on a car battery is 30 months. If the breakdown times of this battery are normally distributed with a mean of 40 months and a standard deviation of 8 ​months, determine the percent of batteries that can be expected to require repair or replacement under warranty.    what ​% of batteries can be expected to require repair or replacement under warranty.​ (Round to two decimal places as​ needed.)

Before changes to its management staff, an automobile assembly line operation had a scheduled mean completion time of 14.2 minutes. The standard deviation of completion times was 1.5 minutes. An analyst at the company suspects that, under new management, the mean completion time, μ, is now less than 14.2 minutes. To test this claim, a random sample of 50 completion times under new management was taken by the analyst. The sample had a mean of 14.1 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 14.2 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.)

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 manufacturer knows that their items have a normally distributed lifespan, with a mean of 4.9 years, and standard deviation of 1.2 years.The 4% of items with the shortest lifespan will last less than how many years?Give your answer to one decimal place.

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 10.2 years, and standard deviation of 3.3 years.The 7% of items with the shortest lifespan will last less than how many years?Give your answer to one decimal place.

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 10.5 years, and standard deviation of 2.7 years.The 3% of items with the shortest lifespan will last less than how many years? Give your answer to one decimal place.

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…