In a newspaper, the number of photos and number of words were counted for 15 different pages. Here are the results.

a) Sketch a scatter plot using ‘Number of photos’ on the horizontal axis and ‘Number of words’ on the vertical axis.
b) From your scatter plot, describe the general relationship between the number of photos and the number of words per page. Use the words positive, negative, strong correlation or weak correlation.

The correct answer is:

Step 1 of 2:
Taking “Number of photos” on the horizontal axis and “Number of words” on the vertical axis, we get the coordinate points as:
(3,852),(2,1432),(1,1897),(2,1621),(6,912),
(4,1023),(5,817),(7,436),(4,1132),(5,1201),
(2,1926),(3,1628),(1,1403),(0,2174),(1,1829)
The scatter plot corresponding to the points are:

Step 2 of 2:
The trend line of the graph is:

Analyzing the graph, it is clear that, as the number of photos increase, the number of words decrease. That is, the slope of the line is negative. This means, they are negatively correlated.
Similarly, the points cluster around the trend line closely and tightly. This indicates that the variables have a strong correlation among the variables x and y.
 

You could find the correlation among the variables even without the trend line. If they increase and decrease together, they have a positive relationship. Or else, it is negative.