Assume the upper arm length of males over 20 years old in the united states is approximately normal with mean 39.2 centimeters (cm) and standard deviation 2.4 cm. use the 68–95–99.7 rule to answer the given questions. (a) what range of lengths covers almost all, 99.7% , of this distribution? enter your answers rounded to one decimal place. from : cm to : cm (b) what percent of men over 20 have upper arm lengths less than 36.8 cm? enter your answer rounded to one decimal place.