A study was conducted to assess the effects that occur when children are exposed to cocaine before birth. Children were tested at age 4 for object assembly skill, which was described as "a task requiring visual-spatial skills related to mathematical competence." The 200 children born to cocaine users had a mean of 7.1 and a standard deviation of 3.1. The 192 children not exposed to cocaine had a mean score of 8.3 with a standard deviation of 3.0. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Let population 1 be children born to cocaine users. Complete parts (a) and (b) below. a. Use a 0.01 significance level to test the claim that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly. Identify the null and alternative hypotheses. O A. Ho: Hy > H2 OB. Ho: H1 = H2 O C. Ho: My H2 H1: 41 = H2 H1 : 11 = H2 H1: H1 = H2 OD. Ho: My = H2 OE. Ho: H1 # H2 OF. HO: M1 = H2 H1 : 41 7 H2 H1 : H1 = H2 H1: 1 1 > 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. the null hypothesis. There sufficient evidence to support the claim that prenatal cocaine exposure is associated with lower scores of four-year-old children on the test of object assembly. b. Test the claim in part (a) by using a confidence interval. The % confidence interval estimate is