Line Graphs

Mrs. Johnson was looking at a chart of the profits from her company.

Why do you think she looks so happy?

SY00079_.WMF (3428 bytes)

This kind of chart is called a line graph. A line graph works the same way that a bar graph works, it just looks different. For some applications, line graphs can make your data look more exciting and dramatic, as it does with Mrs. Johnson's profits.

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

Starting with Day 1, click on the point on the graph that corresponds to Day 1 = 2 cm
(Hint: Watch for the pointing finger!)

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

We mark the point that is in the Day 1 column, and in the 2 cm row.

Now click on the spot that corresponds to Day 2 = 5 cm.

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

We mark the spot over Day 2 so that it's even with 5 cm.

Now click on the spot which corresponds to Day 3 = 8 cm

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

Excellent! Now click on Day 4 = 9 cm.

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

Looking good! One more point to plot: Day 5 = 9 cm

We're going to put this data into the graph:

Height of Plant after applying SuperGro Fertilizer

Day 1: height = 2 cm

Day 2: height = 5 cm

Day 3: height = 8 cm

Day 4: height = 9 cm

Day 5: height = 10 cm

Now we've plotted all the data, finally, we connect all the dots with straight lines. Try tracing them on your screen with your finger, then click here to see how it looks.

Doesn't that look great? What can you say about the growth of this plant?

Let's try interpreting a line graph. Here are the temperatures for the first week in July. Your normal body temperature is 37 degrees Celcius, or 98.6 degrees Fahrenheit, so you can see that some of these days are pretty HOT!

What was the temperature on the second day?

What was lowest temperature during this period?

I guess that lesson is over! You should know a lot more about line graphs!