Chapter 14, Problem 7STP

Interpretation Introduction

Interpretation: The graph which shows a directly proportional relationship is to be determined.

Concept introduction: One type of proportionality connection is referred to as direct proportion. In other words, if the value of one variable increases, the other variable will increase proportionally. Direct proportion is also referred to as direct variation.

Answer to Problem 7STP

The correct option is (A).

The directly proportional relationship graph is given below.

  

Explanation of Solution

The given option of the graphs are as follows:

  

  

  

Reason for the correct option:

Directly proportional graphs are straight-line graphs. When the value of one variable increases, the value of the other variable also increases, and as a result, the straight line maintains the same gradient while one variable continues to get larger. On the other hand, the straight line approaches zero when the value of both variables decreases.

Hence, the correct option is (A).

  

Conclusion

Reason for the incorrect options

Directly proportional graphs are straight-line graphs. But other graphs are not straight lines.