Assume a PC manufacturer wants to measure the performance of its hard disk memory system. One measure of performance is the average time between failures of the disk drive. To estimate this value, a quality control engineer recorded the time between failures for a random sample of 49 disk-drive failures. A summary of the sample statistics was that x-bar = 5,790.36 hours and with sample standard deviation s = 224 hours. Estimate the true mean time between failures with a 90% CI.