1. According tothe WHO report, girls who areone month old have a mean head circumference of36.55 centimeters witha standard deviation of1.17cm.

According toMedscape.com, microcephaly isa head circumference greater than twostandard deviations below the mean. What percentage of1-month oldgirls willbecategorizedashavingmicrocephaly?Howdoyouknow?

Children witha condition called hydrocephalus (informally known as water onthe brain) have a head circumference that is inthe 98thpercentile orgreater. Fora 1-month old girl what head circumference marks the 98thpercentile? (Thismeans that 98% ofthe children have a head circumference thatissmallerthanthismark.)