Answer Happy

A known data set represents a random sample of 186 cases of mothers and their newborns in Florida over a year. We are particularly interested in two variables: weight and smoke, which is provided in the figure below. The weight variable represents the weights of the newborns and the smoke variable describes which mothers smoked during pregnancy. We would like to know, is there convincing evidence that newborns from mothers who smoke have a different average birth weight than newborns from mothers who don't smoke? The researcher will use a significance level of alpha = .01. Smoker Non-Smoker Sample Size 82 104 Stand Dev 1.23 1.76 Mean 6.64 7.27 t -2.75 Significance Level/P-value 0.006

a) Is this a left-tailed, right-tailed, or two-tailed test? Explain. b) Interpret the p-value. c) Compare the p-value to the significance level. Are these results significant? d) Interpret the results of this study for a non-statistical audience.