Suppose a regional computer centre A wants to evaluate the performance of its disk memory system. One measure of performance is the average time between failures of its disk drive. To estimate this value, the centre recorded the time between failures for a random sample of 45 disk-drive failures. The following sample statistics were computed:
BAR x =1768 hours, s = 213 hours
i. Estimate the true mean time between failures with a 90% confidence interval.
ii. If the disk memory system is running properly, the true mean time between failures will exceed 1700 hours. Based on the interval in part (i), what can you infer about the disk memory system?