Heights of adult males are known to have a normal
distribution. A researcher claims to have randomly selected
adult males and measured their heights with the resulting
relative frequency distribution as shown here. Identify two
major flaws with these results.
Relative
Height (cm) Frequency
22%
25%
21%
27%
29%
130-144
145-159
160-174
175-189
190-204
Select all that apply.
A. The relative frequencies were recorded as percents instead of counts.
B. All of the relative frequencies appear to be roughly the same. If they are from a normal distribution, they
should start low, reach a maximum, and then decrease.
C. The classes do not allow for the possibility that an adult male could be between 144 cm and 145 cm tall, or
between 159 cm and 160 cm tall, and so on.
D. All of the relative frequencies are different. If they are from a normal distribution, they should all be exactly
the same.
E. The classes do not allow for the possibility that an adult male could be less than 130 cm tall or greater than
204 cm tall.
OF. The sum of the relative frequencies is 124%, but it should be 100%, with a small possible round-off error.