Question

please help and explain, thank you very much!

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 190 children born to cocaine users had a mean of 7.3 and a standard deviation of 3.0. The 186 children not exposed to cocaine had a mean score of 8.2 with a standard deviation of 3.0. Use this sample data along with a 0.05 significance level to test the claim that prenatal cocaine exposure is associated with lower scores for 4-year olds on the test of object assembly.

Answer 1

Answer: - S2 - 3.0 of 2- S si ni n2 13 (3.0)2 + 190 186 12 to critical value, so. Given ni = 190 z = 7.3 S - 3.0 12 = 186 <, = 82, The null and alternative hypothese are, Ho iM, = M2 HoiM, LM₂ The test statistic t = 7.3 8.2 (3.0) -0.9 0-3094 to critical value is degrees of freedom (df) df = 374 t critical s-tar, a €374, 6.05 (from t- table) ta-tcritical Here, the value of the test statistic ct) ás -2.9089 is Less than the 0.05 level of significance Therefore, there is sufficient evidence to support the claim that parental cocaine exposure ů associated with lower scores of 4 - Yearold children on the test of object assembly, + = -2.9089 = nitna-2 190+186-2 Q=0.05 =-1.65 at