### Home > CC3 > Chapter 7 > Lesson 7.3.3 > Problem7-110

7-110.

An unusually severe increase in gasoline prices may have motivated full-sized pickup truck buyers to purchase a highly fuel-efficient vehicle. Purchase behavior was collected in one area for one year and reported below.

 Low Fuel Prices High Fuel Prices Number of Highly Fuel Efficient Trucks Purchased $392$ $442$ Number of Ordinary Cars and Regular Trucks Purchased $36,929$ $42,255$

1. Complete the row and column totals. What is the independent variable?

The price of gas influences the number of fuel efficient
cars purchased, not the other way around.

Fuel price is the independent variable.

1. Create a conditional relative frequency table. Is there an association between fuel prices and the number of highly fuel-efficient trucks purchased?

Since fuel price is your independent variable, use the column totals to determine conditional relative frequencies.

 Low Fuel Prices High Fuel Prices Number of Highly Fuel Efficient Trucks Purchased 1.1% Number of Ordinary Cars and Regular Trucks Purchased 99.0%