Question

G 11 | | | | | 6.344 Prenatal vitamins and Autism: Researchers studying the link between prenatal vitamin use and autism surveyed the mothers of a random sample of children are 24 - 60 months with autism and conducted another separate random sample for children with typical development. The table below shows the number of mothers in each group who did and did not use prenatal vitamin during the three months before pregnancy (periconceptional period). (Schmidt, 2011) Autism Typical Development Total No vitamin 111 70 181 Vitamin 143 159 302 Total 254 2 29483 (a) State appropriate hypotheses to test for independence of use of prenatal vitamins during the three months before pregnancy and autism. Ho: Pam Poem Ha pampoe vam Home Hari Pem do decimal place What is the p e rsociated with this feet? Ho: Pu Prev Ha Papua (b) Complete the thesis test and the appropriate conclusion Please to four decimal place) The rest of the hypothesis Since the will hypothesis and accept the alternative Sezowe do c h ce to meet the wall hypothes the and the alternative

Answer 1

Answer Date: 15/10/2019 To test the hypothesis is that there is a dependence of use of parental vitamins during the three months before pregnancy and autism at 5% significance level. The null and alternative hypothesis is, H:P1 = P2 Ha:P# P2 The answer option is 3. b) The z-test statistics is, By using Excel software, find z-test statistics with the help of following steps: 1) Import the data. Select the MegaStat from Add-Ins option. Select the Compare Independent Two Proportions from Hypothesis Tests. 2)

Select data input. Select Confidence level, Test difference and alternative hypothesis. Click Ok. Hypothesis test for two independent proportions P1 0.6133 111/181 111. P2 0.4735 143/302 143. Po 0.5259 p (as decimal) 254/483 p (as fraction) 254. X 483 n 181 0.1397 difference 0. hypothesized difference 0.0469 std. error 2.98 z .0029 p-value (two-tailed) From the Excel output, the z-test statistics is 2.98- The p-value for this test is, From the Excel output, the p-value for this test is 0.0029

Decision The conclusion is that the p-value in this context is less than 0.05 which is 0.0029, so the null hypothesis is rejected at 5% level of significance. There is sufficient evidence to indicate that there is a dependence of use of parental vitamins during the three months before pregnancy and autism. The result is statistically significant. The answer option is 3.