Data 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. 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 in their blood is higher than those with high lead levels in their blood. Let /1 represent low lead level. Low Lead Level: n = 21 = 86.90476 s = 8.988352 High Lead Level: n = 78 x = 92.88462 s = 15.34451 Test the claim by constructing a confidence interval One is 95% confident that the true mean of the low lead levels is between (-11.24, -0.7385) and since zero is not contained in the interval we fail to reject null hypothesis. One is 95% confident that the true difference in mean is in the interval (-11.24, -0.7385) and since zero is not contained in the interval we should reject the null hypothesis. One is 95% confident that the true mean of the low lead levels is between (-11.24, -0.7385) and since zero is not contained in the interval we should reject the null hypothesis. One is 95% confident that the true difference in mean is in the interval (-11.24, -0.7385) and since zero is not contained in the interval we fail to reject the null hypothesis