Data Set 5 in Appendix B lists full IQ scores for a random sample of subjects with low lead levels in their blood and another random sample of subjects with high lead levels in their blood. Assume that the two samples are independent simple random samples selected from normally distributed populations. The statistics are summarized below.
Use a 0.05 significance level to test the claim that the mean IQ score of people with low lead levels is higher than the mean IQ score of people with high lead levels. (5 marks)
Construct a 90% confidence interval estimate of the difference between th

Question

Data Set 5 in Appendix B lists full IQ scores for a random sample of subjects with low lead levels in their blood and another random sample of subjects with high lead levels in their blood.  Assume that the two samples are independent simple random samples selected from normally distributed populations.  The statistics are summarized below.  
	Use a 0.05 significance level to test the claim that the mean IQ score of people with low lead levels is higher than the mean IQ score of people with high lead levels. (5 marks)
	Construct a 90% confidence interval estimate of the difference between th