Question

Child Health and Development Studies (CHDS) has been collecting data about expectant mothers in Oakland, California, since 1959. In a fictional study, suppose CHDS conduct a hypothesis test to determine if expectant mothers who smoke have lower birth weight babies. Researchers will test the hypothesis at the 5% significance level. Researchers measure the mean birth weight of a random sample of 50 babies from mothers who do smoke. Assume the mean birth weight for babies is 7.5 pounds with a standard deviation of 1.1 pounds. The hypotheses for the test are: H>0: There is no difference in mean birth weight if expectant mothers smoke. Ha: The mean birth weight is lower than 7.5 pounds if expectant mothers smoke. The p-value for the test turns out to be 0.045. Which of the following is the appropriate conclusion? a. We fail to reject H0. This sample provides significant evidence that expectant mothers who smoke have a lower birth weight b. We fail to reject the H0 this sample does not provide significant evidence that expectant mother who smoke have lower birth with the babies c. We reject Ho this sample does not provide significant evidence that expectant mother who smoke have lower birth weight babies d. We reject Ho. This sample provides significant evidence that expectant mothers who smoke have lower birth weight babies

Answer 1

Solution:-

The hypotheses for the test are:

H₀ u_d> 0: There is no difference in mean birth weight if expectant mothers smoke.

Ha: u_d < 0, The mean birth weight is lower than 7.5 pounds if expectant mothers smoke.

The p-value for the test turns out to be 0.045.

Since the p-value is less than significance level(0.05), hence we have to reject the null hypothesis.

d) We reject Ho. This sample provides significant evidence that expectant mothers who smoke have lower birth weight babies.