Birth weights. A birthweight of less than 3.3 pounds is classified by the NCHS as a very low birth weight. What is the probability that a baby has a very low birth weight for each gestation period. Illustrate each with a graph: ( draw, label, and shade)

a. Under 28 weeks

b. 32 to 35 weeks

Case Study. The National Center for Health Statistics (NCHS) keeps records of many health- related aspects of people, including the birth weights of all babies born in the United States. The birth weight of a baby is related to its gestation period ( the time between conception and birth). For a given gestation period, the birth weights can be approximated by a normal distribution. The means and standard deviations are shown below. Gestation Mean birth Standard period weight deviation Under 28 weeks 1.88 lbs 1.19 lbs 28 to 31 weeks 4.07 Ibs 1.87 lbs 32 to 35 weeks 5.73 lbs 1.48 lbs 36 weeks 6.46 lbs 1.20 lbs 37 to 39 weeks 7.33 lbs 1.09 Ibs 40 weeks 7.72 lbs 1.05 lbs 41 weeks 7.83 lbs 1.08 lbs 42 weeks and over 7.65 lbs 1.12 lbs