Page 31 - THE MATHMATE November 2024

Example 2. A survey of Reptile and Amphibian species from Florida to New York.

State Turtles Lizards Snakes Frogs/ Salamanders
Toads
FL 23 36 44 29 25
GA 22 13 39 28 39
SC 14 12 37 29 32
NC 15 11 36 28 40
VA 18 9 30 24 46
MD 11 6 23 16 19
PA 11 4 20 12 17
NY 12 3 17 13 16

Step 1: Mark the x-axis on the graph. The x-axis is the distance (in this case, the states, in order,
from Florida to New York.

Step 2: The y-axis contains the groups found along the distance (in this case, the turtles, lizards,
snakes, salamanders, and frogs/toads. There are 5 groups. Count the number of squares you have
(here, there are 60) and divide by the number of groups that you have (here, there are 6). This is the
maximum number of squares you could have per group (here, 60 / 6 = 10). I don’t want to go over
10 squares per group, or I will run out of Y axis space.

Now label the y-axis. With 10 squares per group, and 6 groups, I will draw a midline at 5 squares up,
another at 15 squares up, then 25, 35, and a last midline at 45 squares up. Each midline will have a
group name written in on the y-axis, and each midline has 5 squares below it and 5 squares above it
in which to plot the data (Figure 1).

Step 3: Decide how many species are represented by each graph paper square. Use this formula:
(largest data point / 2) / # squares below midline. Start by finding the largest number in the data chart.
Here, it is 46 species of salamanders in Virginia. Take that number and divide by 2 (46 / 2 = 23). For
salamanders in Virginia, you will need space to represent 23 species on either side of (above and below)
the group name.

How many species should be represented by one graph square? Take (46 / 2) and divide by the
number of squares below the midline (5). This is (46 species / 2) / 5 squares = 4.6 species per square,
which we round up to 5. Each square on the graph paper will represent 5 species.

Step 4: Start drawing the kite. Use this formula: (data point / 2) / # individuals per square. With 1
square = 5 species, I will put points both above and below the midline to correspond with the
number of species. In Florida, there are 23 turtle species. Since 23 / 2 = 11.5, you will want to have
a point above the midline (x-axis = Florida / y-axis = Turtles) which represents 11.5 species, and a
point below the midline which represents 11.5 species. Next, 11.5 species / 5 species per square =
2.3 squares. One box is 5 species, 2 boxes is 10 species, 2.3 boxes will represent 11.5 turtle
nd
species (11.5 / 5 = 2.3). Place a point just over the 2 square (2.3 squares up) above the midline,
and a second point 2.3 squares below the midline.

Scctm The MathMate 31 Volume 44/Number 1 October 2024