aishah harun
Jun 9, 2012, 11:21 AM
A sample of 25 male teenagers who shopped at a bookstore showed that they spent an average of RM44 with a standard deviation of RM11. Another sample of 22 female teenagers who shopped at the store showed that they spent an average of RM49 with a standard deviation of RM9. Assuming both population of spending amounts are normally distributed, construct the 99% confidence interval for the difference between the mean amounts spent by all male and female customers at this store. Interpret the interval.