Introduction to the Normal Distribution What proportion of newborns weigh less than 5500 grams at birth? [Hint: Use the Normal Calculator and a shaded sketch.] How little would a baby have to weigh to be among the lightest 2.5% of all newboms? (This number is called the 2.5th percentile of the birth weight distribution.) [Hint: Start with a sketch. You will then need to use the Normal Probability Calculator applet backwards to determine your answer: enter the probability 0.025 in the Prob box, and press Enter.] How much would a baby have to weigh to be among the heaviest 10% of all newborns? [Hint: What percentage weigh less than this?] Find k where P(x > k) = 0.1