Answer Happy

Obstetrics A study was performed of different predictors of low birthweight deliveries among 32,520 women in the Nurses' Health Study". The data in Table 5.5 were presented concerning the distribution of birthweight in the study: TABLE 5.5 Distribution of birth weight in the Nurses' Health Study Category Birthweight (g) N 96 A B с D E < 2500 2500-2999 3000-3499 3500-3999 4000+ 1850 6289 13,537 8572 2272 5.7 19.3 41.6 26.4 7.0 Total 32,520 100.0 1.Xue, F., Willett, W. C, Rosner, B.A., Forman, M. R., & Michels, K. B. (2008). Parental characteristics as predictors of birthweight. Human Reproduction, 23(1), 168–177. Hint: 0.94350 ~ 0.0532,0.94348 ~ 0.0598,0.0572 ~ 0.00325 Questions: 1. Is the data Birthweight continuous or discontinous data? (1.5 p) 2. If 50 women are randomly chosen from the study, what is the probability that exactly 2 will have a low weight delivery (< 2500 g) ? (keep three decimals) (3 p)

An important risk factor for low birthweight delivery is maternal smoking during pregnancy (MSMOK). The data in Table 5.6 were presented relating MSMOK to birthweight. TABLE 5.6 Association between maternal smoking and birthweight category in the Nurses' Health Study Category Birthweight (g) % MSMOK= yes A B с < 2500 2500-2999 3000-3499 3500-3999 4000+ 40 34 25 19 15 D E 3. If 30 women are selected the 3000-3499 g group, then is the probability that more than 10 (that is k>10) women will have smoked during pregnancy? (keep three decimals) (2p) Hint: 10 10 f(k, 30,0.40) < 0.2915, f(k, 30,0.34) < 0.5540, k=0 k=0 10 10 10 f(k, 30,0.25) = 0.8943, f(k, 30,0.19) = 0.9821, f(k, 30,0.15) < 0.9971, ~ k=0 k=0 k=0 where f(k,n,p) n! k!*(n-k)! * p* * (1 – p)n-k