Benchmark 9B
The Mathematical World: Symbolic Relationships
Grades 6-8, page 219

Graphs can show a variety of possible relationships between two variables. As one variable increases uniformly, the other may do one of the following: increase or decrease steadily, increase or decrease faster and faster, get closer and closer to some limiting value, reach some intermediate maximum or minimum, alternately increase and decrease indefinitely, increase or decrease in steps, or do something different from any of these.
 

NSES Content Standard A 
Science as Inquiry: Abilities necessary to do scientific inquiry
Grades 5-8, page 145
Think critically and logically to make the relationships between evidence and explanations. Thinking critically about evidence includes deciding what evidence should be used and accounting for anomalous data. Specifically, students should be able to review data from a simple experiment, summarize the data, and form a logical argument about the cause-effect relationships in the experiment. Students should begin to state some explanations in terms of the relationship between two or more variables.