The statement is telling what portion of the total has both of the two specified characteristics.
B
b
The statement is describing what portion of a group with a given characteristic also has another characteristic.
C
c
The statement is telling what portion of the total has a specified characteristic.
D
d
The statement is describing what portion of a group with a given characteristic also has another characteristic.
E
e
The statement is describing what portion of a group with a given characteristic also has another characteristic.
F
f
The statement is telling what portion of the total has both of the two specified characteristics.
A
a
Joint relative frequency.
B
b
Conditional relative frequency.
C
c
Marginal relative frequency.
D
d
Conditional relative frequency.
E
e
Conditional relative frequency.
F
f
Joint relative frequency.
Practice makes perfect
a
We are asked to classify each statement as describing a joint, marginal, or conditional relative frequency. To do so, we must remember the following definitions.
A joint relative frequency tells what portion of the total has both of the two specified characteristics.
A marginal relative frequency tells what portion of the total has a specified characteristic.
A conditional relative frequency describes what portion of a group with a given characteristic also has another characteristic.
The given statement is telling us what portion of the total number of drivers were considered younger and a high accident risk. It is joint relative frequency.
b
This statement is describing what portion of the older drivers were also considered a high accident risk. This is an example of a conditional relative frequency.
c
This time, the statement is telling us what portion of the total number of drivers were classified as younger. Because this is only one characteristic, it is a marginal relative frequency.
d
The next statement describes what portion of respondents who preferred the incumbent were men. This is a portion of a group which also has another characteristic and is, therefore, a conditional relative frequency.
e
Now, the statement is talking about the portion of women who preferred the challenger. Once again, this is describing a portion of a group with yet another characteristic in common. It is also a conditional relative frequency.
f
The final statement is telling what portion of the total were men and preferred the challenger. This is a joint relative frequency.
