Hemoglobin determinations were made on 15 animals exposed to a harmful chemical. The following observations were recorded:

15.6,	14.8,	14.4,	16.6,	13.8,	14.0,	17.3,	17.4,
18.6,	16.2,	14.7,	15.7,	16.4,	13.9	14.8

At 5% level of significance, test if the Hemoglobin levels in these exposed animals is less than 17 units. Construct 95% confidence interval for the population mean hemoglobin determinations and interpret the result. Can you use this confidence interval to test the above null hypothesis?