A computer manufacturer estimates that its line of minicomputers has, on average, 8.7 days of downtime per year. To test this claim, a researcher contacts seven companies that own one of these computers and is allowed to access company computer records. It is determined that, for the sample, the average number of downtime days is 5.6, with a sample standard deviation of 1.3 days. Assuming that number of downtime days is normally distributed, test to determine whether these minicomputers actually average 8.7 days of downtime in the entire population. Let α = .01.

A computer manufacturer estimates that its line of minicomputers has, on average, 7.3 days of downtime per year. To test this claim, a researcher contacts seven companies that own one of these computers and is allowed to access company computer records. It is determined that, for the sample, the average number of downtime days is 4.3, with a sample standard deviation of 1.3 days. Assuming that number of downtime days is normally distributed, test to determine whether these minicomputers actually average 7.3 days of downtime in the entire population. Let α = .01. Appendix A Statistical Tables (Round your answer to 2 decimal places.) The value of the test statistic is enter the value of the test statistic and we choose between reject and fail to reject the null hypothesis                                                           .

A newly hired human resource analyst proposes to senior management that the number of employee sick days could be reduced by converting to a flex-time work schedule.  Assume that historical records show that the population mean for employee sick days is 5.28 days with a population standard deviation of 2.14 days.  Senior management agrees to a one-year pilot study involving fifty employees working a flex-time schedule.  After one-year, the analyst reports to management that the fifty employees in the study averaged 4.68 sick days during the year.  Does the flex-time work schedule reduce employee sick days?   What are the appropriate null and alternative hypotheses for this study?     Assuming that the H0 is true, what is the probability of the analyst arriving at these results?  (i.e., what is the p-value?)  Does the flex-time work schedule reduce employee sick days?               Using a 0.05 level of significance, what is the necessary value of the test statistic to justify rejecting…

A national online business magazine reports that the average cost of a speeding ticket in Miami, including court fees, is $220. A local police department claims that this amount has increased. To test their claim, they collect data from a simple random sample of 16 drivers who have been fined for speeding in the last year. Assuming that the distribution of speeding ticket costs is normally distributed and the population standard deviation is $13, is there sufficient evidence to support the police department’s claim at the 0.02 level of significance?