Average lifetime of a brand of smart phone is determined by

Average lifetime of a brand of smart phone is determined by measuring working hours of 12 different sets of this brand. The following data is collected (all measurements in hours): (5785, 5961, 5749, 5712, 5598, 6112, 5805, 6003, 5599, 5832, 5689, 5760) Estimate the population mean and 90% confidence Interval on the mean.

Solution

Average lifetime of a brand of smart phone is determined by measuring working hours of 12 different sets of this band \' [5785 5961 5749 5712 5598 6112 5805 6003 5599 5832 5689 5760] hours Sum of lifetime =69605 hours Average of lifetime= 5800.4 hours 90 % confidence interval on the mean = 5220.4 hours