Subscribe:

## Sunday, November 13, 2011

### Anita's Graphing Post

Line Graphs

Advantage: A line graph's advantages are that it is useful for comparing a set of data overtime. For example, your test scores for Math for a year. It is also good for finding a trend. A trend is a line of course or a pattern of events.

Disadvantage: The disadvantages of a line graph is that if the data is not exactly on an interval, the data is difficult to determine, and when you chart it the data is fairly inaccurate.

Bar Graphs

Advantage: The advantages of a bar graph is that it is very good for comparing data across categories.

Disadvantage: The disadvantages of a bar graph are similar to the line graph's disadvantages. When the data is not exactly on an interval, the data can easily be misinterpreted.

Pictographs

Advantage: The advantages of a pictograph is that it is useful for giving visual information, and it can be easily seen and interpreted with symbols.

Disadvantage: The disadvantages of a pictograph is that when the pictures are cut in small pieces, it is not very accurate or easily understood. For example, if you were to cut a picture in 1/3, it will look as if you cut it into halves.

Double Bar Graphs

Advantage: The advantages of a double bar graph is that it is good for comparing two sets of data across categories. That way you can see the comparison between two sets of data.

Disadvantages: The disadvantages of a double bar graph is that the data is hard to interpret if it is not precisely on the interval. A double bar graph is almost the same as a bar graph.

Advantage: It is best for comparing data by comparing to the whole using percentage.

Disadvantage: The disadvantages of a circle graph are that this graph is very difficult and time consuming to make, and if the data is placed into a category named 'Other', you would not know what to categorize that data in.

2. How can graphs be misleading. Show 3 ways.
A graph can be misleading if when you make it one bar wider;

Circle Graphs

You can put a
break in the y-axis;

Or you can make different pictures in a pictograph larger than the other pictures.

2a) The following chart shows Pizza Sub Sales over a month. What 2 graphs would show the information accurately? A bar graph and a line graph.

2b) If you were selling Pizza Subs would you continue? How does your graph explain your answer.

I would continue selling Pizza Subs because the sales are going up, and the number of items sold are increasing.

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?

I would choose the line graph, because you can easily see the the sales becoming greater, and the trend is also easier to see.