Year The National Center for Health Statistics (NCHS) keeps Gestation Mean birth Standard record of many health-related aspects of people. including the both weights of all babies born in the United States period weight deviation The birth weight of a baby is related to its gestation Under 28 Weeks 1.88 lb 1.19 1b renod (the time between conception and birth). For a given 28 to 31 Weeks 4.07 lb 1.87 lb elation penod. the birth weights can be approximated by a normal distribution. The means and standard deviations of 32 to 35 Weeks 5.73 lb 1.48 lb the birth weights for various gestation periods are shown at 36 Weeks 6.46 lb 1.20 lb the night 37 to 39 Weeks 7.33 1b 1.09 lb One of the many goals of the NCHS is to reduce the 40 Weeks 7.72 (b 1.05 1b percentage of babies hom with low birth weights As you can see 41 Weeks 7.83 lb 1.08 1b from the graph at the upper right the problem of low birth 42 Weeks and over 7.65 lb 1.12 1b saghts increased from 1928 to 2002 EErcises L The distributions of birth weights for three gestation 2. What percent of the babies born with each gestation penods are shown. Match the curves with the period have a low birth weight (under 5.5 pounds)? gestation periods. Explain your reasoning Explain your reasoning. (a) (a) Under 28 weeks (b) 32 to 35 weeks (c) 37 to 39 weeks (d) 42 weeks and over 3. Describe the weights of the top 10% of the babies born with each gestation period. Explain your reasoning. (a) 37 to 39 weeks (b) 42 weeks and over (b) 4. For each gestation period, what is the probability that a baby will weigh between 6 and y pounds at birth? (a) 32 to 35 weeks (b) 37 to 39 weeks (c) 42 weeks and over 5. A birth weight 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? (a) Under 28 weeks (b) 32 to 35 weeks (c) 37 10 39 weeks