According to the WHO report, girls who are one month old have a mean head circumference of 36.55 centimeters with a standard deviation of 1.17 cm. 1) Ann is concerned that her daughter’s head is small. Her daughter has a head circumference of 34.25 centimeters when she is one-month old. If we consider measurements more than 2 standard deviations from the mean as unusual, is Ann’s daughter’s head measurement unusually small? Support your answer.
2) According to Medscape. com, microcephaly is a head circumference more than two standard deviations below the mean. What percentage of 1-month old girls will be categorized as having microcephaly? How do you know?