Look at the graph below, showing the average concentrations of four indica- tors in a lake over 60 years. Based on the graph data only, decide if you agree
or disagree with the three statements below, and explain why. The following
definitions may help you evaluate the claims: .
A correlation is a relationship between one event or action and another. A
positive correlation means that as one event or action becomes large, the other
also becomes large, and vice versa. A negative correlation means that when one
event or action becomes larger, the other becomes smaller, and vice versa.
A causal relationship between two correlated events is when one event
(called the cause) directly produces another event (called the effect). In a
causal relationship, the cause(s) alone produce the effect.