Determine the probability that a randomly selected baby weighs between 3000 and 4000 grams at birth.

[Hint: Start with a sketch. Use the applet and check the second box and enter both X values.]

Data from the National Vital Statistics System indicate that in 2004 there were 4,112,052 births in the United States. A total of 331,772 babies were of low birth weight. From these data, what proportion of births in 2004 were of low birth weight?

How does this proportion compare to the probability calculated by the normal approximation?