<p>AP Statistics Name______Normal Distribution Review WS </p><p>1. Weights of newborn babies in the United States are normally distributed with a mean of 3420 g and a standard deviation of 495 g. A newborn weighing less than 2200 g is considered to be at risk, because the mortality rate for this group is at least 1%. </p><p> a. What percentage of newborn babies are in the “at-risk” category? </p><p> b. If Wilkes Regional Medical Center has 900 births in a year, how many of the babies can they expect to be in the “at-risk” category.</p><p>2. One classic use of the normal distribution is inspired by a letter to “Dear Abby” in which a wife claimed to gave given birth 308 days after a brief visit from her husband, who was serving the Navy. The lengths of pregnancies are normally distributed with a mean of 268 days and a standard deviation of 15 days. Given this information, find the probability of a pregnancy lasting 308 days or longer. What does the result suggest?</p><p>3. Using the information about length of pregnancies in #2, answer the following question.</p><p>If we stipulate a baby is premature if the length of the pregnancy is in the lowest 4%, find the length that separates premature babies from those that are not premature. 4. Scores on the biology portion of the Medical College Admissions Test were normally distributed with a mean of 9.1 and a standard deviation of 2.1 in 2005. a. What percentage of scores were above 8.5 in 2005, the minimum score required for admission to the Providence School of Medicine?</p><p> b. What percentage of the scores were between 7.5 and 9.0 in 2005?</p><p> c. What score was at the D2 in 2005? Be sure to write a sentence to interpret this answer.</p><p> d. Suppose that in 2007, 10% of all scores on this test were below 2.65 and 15% of scores were above 9.85. Show how you can use this information to find the mean and standard deviation. Assume the scores were roughly symmetric and unimodal.</p><p> e. In 2008, the mean score on this test was 8.85 and D4 was 8.43. Find the standard deviation of the scores and write a sentence to interpret the meaning of the standard deviation in the context of the problem.</p>