Problem Page The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 70 new hires took the test and scored a mean of 113.1 points with a standard deviation of 14. Last year, 85 new hires took the test and scored a mean of 116.9 points with a standard deviation of 15.3. Assume that the population standard deviations of the test scores of all new hires in the current year and the test scores of all new hires last year can be estimated by the sample standard deviations, as the samples used were quite large. Construct a 95% confidence interval for −μ1μ2, the difference between the mean test score μ1 of new hires from the current year and the mean test score μ2 of new hires from last year. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to at least two decimal places.
What is the lower limit of the 95% confidence interval
What is the upper limit of the 95% confidence interval
Problem Page The human resources department of a consulting firm gives a standard creativity test to...
The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 70 new hires took the test and scored a mean of 112.5 points with a standard deviation of 15.2. Last year, 55 new hires took the test and scored a mean of 117.5 points with a standard deviation of 18. Assume that the population standard deviations of the test scores of all new hires in...
Question #21 / 25 The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 55 new hires took the test and scored a mean of 113.2 points with a standard deviation of 15.3. Last year, 90 new hires took the test and scored a mean of 116.8 points with a standard deviation of 17.5. Assume that the population standard deviations of the test scores of...
The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 65 new hires took the test and scored a mean of 113 points with a standard deviation of 13.8. Last year, 90 new hires took the test and scored a mean of 117 points with a standard deviation of 16.3. Assume that the population standard deviations of the test scores of all new hires in...
The human resources department of a consulting firm gives a standard creativity test to a randomly selected group of new hires every year. This year, 70 new hires took the test and scored a mean of 113.3 points with a standard deviation of 16.2. Last year, 95 new hires took the test and scored a mean of 116.7 points with a standard deviation of 17.3. Assume that the population standard deviations of the test scores of all new hires in...
00 Pilots who cannot maintain regular sleep hours due to their work schedule often suffer from insomnia. A recent study on sleeping patterns of pilots focused on quantifying deviations from regular sleep hours. A random sample of 15 commercial airline pilots was interviewed, and the pilots in the sample reported the time at which they went to sleep on their most recent working day. The study gave the sample mean and standard deviation of the times reported by plots, with...
The standard deviation of test scores on a certain achievement test is 11.1. A random sample of 60 scores on this test had a mean of 75.4. Based on this sample, find a 95% confidence interval for the true mean of all scores. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the lower limit of the 95% confidence interval? What is the upper limit...
(4)Five hundred students from a local high school took a college entrance examination. Historical data from the school record show that the standard deviation of test scores is 40. A random sample of thirty- six students is taken from the entire population of 500 students. The mean test score for the sample is three hundred eighty. Find (a) 95% confidence interval for the unknown population mean test score. (b) 95% confidence interval for the unknown population mean test score if...
64 college students took a placement test. Their mean score was 29.5 points with a standard deviation of 7.3 points. Construct a 95% confidence interval for the mean score on this placement exam for all students.
An existing inventory for a test measuring self-esteem indicates that the scores have a standard deviation of 12. A poychologist gave the self-esteem best to random sample of 100 individuals, and their mean score was 65. Construct a 90% confidence interval for the true mean of all test scores. Then complete the table below. Carry your intermediate computations to at least three decimal places. Round your answers to one dedmal place. What is the lower limit of the 90% confidence...
An existing inventory for a test measuring self-esteem indicates that the scores have a standard deviation of 8. A psychologist gave the self-esteem test to a random sample of 100 individuals, and their mean score was 60. Construct a 99% confidence interval for the true mean of all test scores. Then complete the table below Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. What is the lower limit of the 99%...