Kiran collects data about the number of trees on school property and the average standardized test scores for those schools. Kiran says, "The scatter plot between the number
of trees on a school property and student standardized tests scores shows a strong and
positive correlation. An increase in the number of trees on school property causes the
students to score better on standardized tests."
What is wrong with the last sentence of Kiran's statement? Explain your reasoning.