The upper arm length of males over 20
years old in the United States is approximately Normal with mean 39.1
centimeters (cm) and standard deviation 5.1
cm. Use the 68−95−99.7
rule to answer the following questions. (Start by making a sketch of the Normal distribution for upper arm lengths for this population.)
A normal plot shows the range of Iowa test scores for 68% of the data, 95% of the data and 99.7% of the data. About 68% of the distribution of scores ranges from 5.29 to 8.39. About 95% of the distribution of scores ranges from 3.74 to 9.94. About 99.7% of the distribution of scores ranges from 2.19 to 11.49. There is an annotation that One standard deviation is 1.55 and another annotation that 2.5% of sores are below 3.74.
What percentage of men over 20
have upper arm lengths greater than 44.2 cm?
Provide your answer to one decimal place.
