The IQ scores for a random sample of subjects with low lead levels in their blood and another n X S random sample of subjects with high lead levels in their blood were collected. The statistics are Low Lead Level H1 87 91.69151 15.57305 summarized in the accompanying table. Assume that the two samples are independent simple High Lead Level H2 25 87.84931 8.84742 random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Complete parts (a) to (c) below. a. Use a 0.05 significance level to test the claim that the mean IQ score of people with low blood lead levels is higher than the mean IQ score of people with high blood lead levels. What are the null and alternative hypotheses? Assume that population 1 consists of subjects with low lead levels and population 2 consists of subjects with high lead levels. O A. HO: H1 # H2 O B. HO: H1 = H2 Hy: 19 > H2 H1: H1 # H2 O C. HO: My SH2 OD. HO: H1 = H2 Hy: H 1 > H2 H1: 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. A. Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with low lead levels have higher IQ scores. O B. Reject the null hypothesis. There is sufficient evidence to support the claim that subjects with low lead levels have higher IQ scores. O C. Reject the null hypothesis. There is not sufficient evidence to support the claim that subjects with low lead levels have higher IQ scores. O D. Fail to reject the null hypothesis. There is sufficient evidence to support the claim that subjects with low lead levels have higher IQ scores. b. Construct a confidence interval appropriate for the hypothesis test in part (a).