Use the points (1, 20), (2,18), (4,15), (6, 12), (7,12), (8,7), (8,3), (9,6) and (9, 1) for your data points. Call the left number in the paired numbers within parenthesis the independent data value and the right number the dependent data value. Call the set of data points the sample data points.
Construct a table with two columns and nine rows for the nine pairs of data points in Step 1. Label the first column, mango consumption per week. Label the second column, incidence of cancer per 1,000 people. Place the left element of the first paired point (1, 20), 1, in the left column of the first row of the table. Place the right element of the first data point, 20, in the right column of the first row in the table. Place the second data point (2, 19), in the second row of the table in the same fashion. Repeat this procedure until all of the data points are in the table.
Draw a horizontal line in the center of your paper that extends 1 inch from the left of the edge of the paper to 1 inch from the right edge of the paper. Call this line the x-axis. Write the label, "Number of Mangoes," underneath the x-axis. Center this label between the two endpoints of the x-axis.
Draw a vertical line that extends from the left endpoint of the x-axis to 1 inch from the top edge of the paper. Call this line the y-axis. Write the label, "Cancer Rate per 1,000," to the left of the y-axis. Center this label between the two endpoints of the y-axis.
Measure 1/2-inch intervals on the x-axis starting from its left endpoint. Draw a small vertical line at every 1/2-inch interval along the x-axis. Write the number 0 below the left endpoint on the x-axis, Write the number 1 below the first vertical division line you just drew. Write 2 below the second vertical line. Continue writing the numbers in numerical order until you reach 10.
Measure 1/2-inch intervals on the y-axis starting from its lower endpoint. Draw a small horizontal line at every 1/2-inch interval on the y-axis line. Write the number 0 to the left of the lower endpoint of the y-axis. Write the number 1 below the first horizontal division line you just drew. Write the number 2 below the second horizontal division line. Continue writing the numbers in numerical order until you reach 20.
Locate the number 1 that is labeled on the x-axis. Draw a very light line vertical upward that extends to the top of the graph. Locate the number 20 on the y-axis. Draw a very light horizontal line such that it passes through the vertical line you just drew. Darken with your pencil the point where the two lines intersect. Write "(1,20)" next to this point to indicate that the point is the first data element in the table, the point (1.20). Continue in this fashion to plot and label every point on your scatter plot.