Correlation is a value between −1 and 1 which describes how the values in the data relate to each other.
You can determine if a correlation is negative or positive depending on the direction made on a scatter plot.
Upward Slope
=
Positive Correlation
Downward Slope
=
Negative Correlation
No Direction
=
Zero Correlation
The proper logic to follow would be, as your study time increases, your grade also increases.
This means that Study Time and Grades have a direct variation, or a positive correlation.
Using the guide above, we can determine which of the scatter plots is positive
Plot A
The scatter plot displays an upward slope on the first half, and a downward slope on the second half. Therefore, the correlation is positive on the first half, and negative on the second half.
Plot B
The scatter plot displays a downward slope. Therefore, the correlation is negative
Plot C
The scatter plot does not display any visible direction. Therefore, the correlation is zero.
Plot D
The scatter plot displays an upward slope. Therefore, the correlation is positive
Therefore, plot D displays the correlation between Study Time and Grades.
Question 4 of 6
4. Question
Which of the following scatter plots indicate the correlation r=−0.8?
Correlation is a value between −1 and 1 which describes how the values in the data relate to each other.
You can determine if a correlation is negative or positive depending on the direction made on a scatter plot.
Upward Slope
=
Positive Correlation
Downward Slope
=
Negative Correlation
No Direction
=
Zero Correlation
Since the correlation is negative and is close to −1, the correct scatter plot would have a downward slope and the plots should be the least scattered.
Plot A
The scatter plot displays a downward slope and the plots are loose. Therefore, the correlation of this plot would be negative and is close to 0.
Plot B
The scatter plot displays an upward slope and the plots are loose. Therefore, the correlation of this plot would be positive and is close to 0.
Plot C
The scatter plot displays a downward slope and the plots are compressed. Therefore, the correlation of this plot would be negative and is close to −1.
Plot D
The scatter plot displays an upward slope and the plots are compressed. Therefore, the correlation of this plot would be positive and is close to 1.
Therefore, plot C would be the most accurate scatter plot to indicate the correlation r=−0.8.
Question 5 of 6
5. Question
Match the correlation coefficient to each of the scatter plots.
