## Thursday, November 10, 2011

### Hannah's Graphing Post

1. Types Of Graphs

Bar Graph
advantage: Best for comparing data across categories.
disadvantage: Depending on the scale or interval, the exact number is not clear or could be difficult to identify.

Double Bar Graph
advantage: Best for comparing two sets of data across categories.
disadvantage: If a double bar graph has too many series of data, it can be confusing to read and depending on the scale or interval, the exact number is not clear.

Circle Graph
advantage: Best for comparing categories to the whole using percents. The sum of the percents in a circle graph is 100%.
disadvantage: Difficult to understand without labels and you must perform calculations to determine of each category. It will be difficult to read and label if there is a lot of series of data.

Line Graph
advantage: Best for showing changes in data over time. Line graph shows you a trend.
disadvantage: Just like a bar graph and double bar graph, depending on the scale or interval the exact number is not clear.

Pictographs
advantage: Best for comparing data that can be easily counted and represented using symbols.
disadvantage: Hard to find the exact amount of partial symbols.

Example 1: Distorting the scale (putting a break in the y-axis)

Example 2: Distorting the visuals (making a symbol appear larger than the others)

Example 3: Distorting the size of bars (making a bar wider or in other words adding more area inside a bar, or making a bar appear 3D)

3.
a) The following chart shows Pizza Sub Sales over a month. What 2 graphs would show the information accurately?

A line graph and a bar graph would show the information accurately.

b) If you were selling Pizza Subs would you continue? How does your graph explain your answer.

I would continue selling Pizza Subs because the items sold each week is increasing. Using a line graph, it would show changes in the data over time and the trend would be going up.

4. Below you see 2 different examples of graphs showing healthy choices sold at the canteen. If you had to convince Mrs. Mota that we should continue selling healthy choices which graph would you choose?

If I had to convince Mrs.Mota that we should continue selling healthy choices, I would choose the line graph because it clearly shows that the trend is increasing.

a) Change each graph so that your information looks even MORE impressive. You may not change the data just the graphs.

Here is a game/link to practice Bar Graphs.

Here is a video about Bar Graphs