Investigating Relationships between Variables: Interpreting Scatterplots. Examining Relationships. Is there a relationship between the number of minutes the 1992 Dream Team basketball player was on the court and the number of points he scored?
We notice that a line, rather than a curve appears to summarize the data. (we’ll learn some additional ways to check this aspect later)
The scatterplot at the right shows horsepower ratings for several models of vehicles and the corresponding gas mileage. The scatterplot indicates that the relationship between these variables is negative
There appears to be a moderately strong* relationship between the number of minutes a player is on the court and the number of points he scored. As the time on court increases, so does the points scored, indicating a positive association between these variables.
*Note: we will learn some numeric guidelines on strength in the next lesson about correlation.