Graphing

Did you have a growth chart as a baby? This graph tells us how much weight (in Kilograms) a baby gained in 36 months.

This graph shows us the increase and the number of people using Facebook from March 2004 to March 2007

This graph shows us the number of people who have a certain type of pet. Types of Pets

What does this graph show us?

A graph can be used to make comparisons What conclusion can you make?

This pie chart shows how much time Teensy spent writing her English essay.

Rules for constructing a graph 1. Always provide a title for your graph Without a title the data has no meaning

Always label the X and Y axis

The independent variable is what the investigator deliberately varies during the experiment. It is chosen because the investigator thinks it will affect the dependent variable. This is represented on the X axis. The dependent variable is what the investigator measures (or counts or records). It is what the investigator thinks will vary during the experiment. For example, he may want to study peanut growth. One possible dependent variable is the height of the peanut plants. This is represented on the Y axis. Time is usually a variable represented on the X axis. It could be time in seconds, minutes, months or years. Another way to remember the Y axis is that is represents the change that is taking place.

What Type of Graph? Bar Graph – comparing groups Line Graph – change over time Pie/Circle Graph- parts of a whole Scatter Plot – correlation of variables Histogram – distribution of data Video

Do Now 8/31-9/1 What are the independent and dependent variables in these two experiments? Are either of these graphs missing information? What?