Answer:
C. Those who have a car tend to have a cell phone.
Step-by-step explanation:
The relative frequency for a data set n is calculated by dividing each frequency 
by n.
We have a table that relates the use of cars and cell phones.
First, we take from the table the population that has a car.
Then, of the students who have a car, 12 have a cell phone and 6 do not have a cell phone.
Then we calculate the relative frequencies 
for those who have a cell phone and those who do not.
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Relative frequency Students with car n = 18.
-------------------------------------------------- --------------------------------------
C<em>ell phone No cell phone Total n</em>
12/18 6/18 18
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Relative frequency Students with car n = 18.
-------------------------------------------------- --------------------------------------
C<em>ell phone No cell phone Total n</em>
0.666 0.333 18
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Most students who have a car also have a cell phone.
Now we calculate the relative frequency for students who do not have a car.
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Relative frequency Students without a car n = 7
-------------------------------------------------- --------------------------------------
<em>Cell phone No cell phone Total n</em>
2/7 5/7 7
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Relative frequency Students without a car n = 7
-------------------------------------------------- --------------------------------------
<em>Cell phone</em> <em> No</em> <em>cell phone Total n</em>
0.286 0.714 7
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Most students who do not have a car do not have a cell phone either.
<em>Then these data suggest that. Those who have a car tend to have a cell phone.</em>
Option C
