In the United States, the mean birth weight for boys is 3.41 kg, with a standard deviation of 0.55 kg. (Source: cdc.com.) Assuming that the distribution of birth weight is approximately normal, find the following using a table, calculator, or software.
a. A baby is considered of low birth weight if it weighs less than 2.5 kg. What proportion of baby boys in the United States are born with low birth weight?
b. What is the z-score for a baby boy that weighs 1.5 kg (defined as extremely low birth weight)?
c. Typically, birth weight is between 2.5 kg and 4.0 kg. Find the probability a baby boy is born with typical birth weight.
d. Matteo weighs 3.6 kg at birth. He falls at what percentile?
e. Max’s parents are told that their newborn son falls at the 96th percentile. How much does Max weigh?