Answer Happy

5. Listed in the data table are IQ scores for a random sample of subjects with medium lead levels in their blood. Also listed are statistics from a study done of IQ scores for a random sample of subjects with high lead levels. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Click the icon to view the data table of IQ scores. a. Use a 0.05 significance level to test the claim that the mean IQ scores for subjects with medium lead levels is higher than the mean for subjects with high lead levels. What are the null and alternative hypotheses? Assume that population 1 consists of subjects with medium lead levels and population 2 consists of subjects with high lead levels. O A. Ho: H1 H2 H:H *H2 OC. Ho: M1 = P2 H:H1 H2 OB. Ho: My #H2 H:H1 H2 OD. Ho H1 H2 H:H1 H2 The test statistic is (Round to two decimal places as needed.) The P-value is (Round to three decimal places as needed.) State the conclusion for the test. O A. Fail to reject the null hypothesis. There is sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores. OB. Reject the null hypothesis. There is sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores. OC. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores. OD. Reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with medium lead levels have higher IQ scores. b. Construct a confidence interval suitable for testin the claim that the mean IQ scores for subjects with medium lead levels is higher than the mean for subjects with high lead levels. <H1 H2 <1 (Round to two decimal places as needed.) Does the confidence interval support the conclusion of the test? (1) because the confidence interval contains (2)

1: IQ Scores Medium Lead Level High Lead Level 72 n2 = 11 90 92 X = 89.641 S2 = 9.702 85 85 97 83 92 96 111 91 (1) O No, O Yes, (2) O only positive values. O only negative values. O zero.