The mean birth length for U.S. children born at full term (after 40 weeks) is 52.2 cm (about 20.6 inches). Suppose the standard deviation is 2.5 cm and the distributions are unimodal and symmetric. 

a. What is the range of birth lengths (in centimeters) of U.S.-born children from one standard deviation below the mean to one standard deviation above the mean? 

b. Is a birth length of 54 cm more than one standard deviation above the mean?