What variables show a direct relationship? Check all that apply.

1. the speed of a car and the distance traveled

2. the elevation above sea level and the air temperature

3. the number of students in a cafeteria and the amount of food consumed

4. the mass of an icicle and the time it takes to melt

5. the distance a planet is from the Sun and that planet’s temperature

6. the mass of a space shuttle and its acceleration through space

By direct relationship , it is meant that if one quantity increases the other one should also increase and when a quantity decreases the other quantity must also decrease.

In other worlds there must a directly proportional relationship between two quantities.

Hence, except option 2 where the relationship between the number of students and the amount of food consumed is inversely proportional all other options are directly proportional.

Thus, 1,2,4 & 5 are correct