Connect the Dots
Line graphs are useful for finding patterns or trends in the data. Good examples of a line graph are tracking weather and money fluctuations.
Like the bar graph, the line graph has a vertical axis and a horizontal axis; however, unlike the bar graph, the line graph data only moves horizontally. There is no vertical line graph. Since there is no vertical version of the line graph, you will always see the units of measurement on the vertical axis and items being measured/tracked on the horizontal axis. Each data point is notated by a dot. Once all dots have been plotted, you simply connect the dots.
Tracking Liesel’s Savings Account
We will track the fluctuations of Liesel’s savings account for the first half of the year. Become familiar with the line graph’s title like you would a bar graph. See the main title and the titles on the axes. These titles are your clues to successfully interpreting the information.
From this line graph, we can see that her account started at approximately $4,500. She was steadily able to accumulate savings over the next two months and then in April, the savings account took a drastic dip. She must have made a big purchase in April. In May, Liesel gets back on track saving money. In the last month tracked, June, the account takes another hit, but it isn’t as bad as the one in April. Her savings account ends up somewhere between $2,000 and $3,000.
If this was a exam graph, common questions you could be asked are:
- Which month had the highest amount saved? In March, Liesel has $6,000, which is the highest amount recorded during the six month period.
- Which month is the lowest amount saved? In April, the account dropped to $2,000, which is the lowest amount recorded during the six month period.
- What is the difference between the highest and lowest amount saved? Subtracting March from April, the difference is $4,000.