In: Statistics and Probability
For several years, evidence had been mounting that folic acid reduces major birth defects. In a study, doctors enrolled women prior to conception and divided them randomly into two groups. One group, consisting of 2722 women, took daily multivitamins containing 0.8 mg of folic acid; the other group, consisting of 2107 women, received only trace elements. Major birth defects occurred in 31 cases when the women took folic acid and in 47 cases when the women did not. a. At the 1% significance level, do the data provide sufficient evidence to conclude that women who take folic acid are at lesser risk of having children with major birth defects? b. Is this study a designed experiment or an observational study? Explain your answer.
Calculate the test (Round to two decimal place
Let sample 1: women took folic acid
sample 2: women did not take folic acid
(a)
At the 1% significance level, the data provides sufficient evidence to conclude that women who take folic acid are at lesser risk of having children with major birthdefects.
(b)
Study is experimental study because researcher gave some treatment to some women.