Construct a 90% confidence interval estimate for the difference in the number of pages produced by the two different cartridges described in Exercise 14 above.
In exercise
A consumer group tested two brands of inkjet printer cartridges for a particular printer to see whether there was a difference in the number of pages produced before the cartridge ran out of ink. The printers were tested in a random sample of offices where they were used for printing invoices. Brand A cartridges produced an average of 862 pages, with a standard deviation of 362, for a sample size of 31. Brand B cartridges produced an average of 731 pages, with a standard deviation of 223, for a sample size of 25. Is there evidence of a difference in the number of pages produced by the two brands of cartridges?