2.3 Lesson 3 Use Scatter Plots to Analyse Data

4.5 4 3.5 3 2.5 2 1.5 1 0.5 Dependent Variable - Y 1 2 3 4 Independent Variable - X

Objective: Purpose of experiment Hypothesis: Educated guess or theory Procedure: a step-by-step ordered list of how to conduct the experiment Observations: collections of data (may be qualitative or quantitative) Conclusions: making an inference (conclusion made by reasoning and data) based on observations.

When looking at relationships between two variables (Ex When looking at relationships between two variables (Ex. forearm length and handspan) the variables can be dependent or independent. Dependent variable: a variable that is affected by another variable. * Usually on the y-axis. (ex. handspan is affected by forearm length)

Independent Variable: a variable that affects the value of another variable. Ex. When forearm length changes so does handspan. *Usually on x-axis. Together the independent and the dependent variable make an ordered pair (x , y) # on x-axis # on y-axis

Sometimes the ordered pairs are outliers (a point that does not follow the flow of the other data points on a graph). This can be from error in data collection or just by chance for certain values of the variables.

Circle the Outlier 4.5 4 3.5 3 2.5 2 1.5 1 0.5 Dependent Variable - Y Dependent Variable - Y 1 2 3 Independent Variable - X 4

Questions: Identify the Independent and the dependent variable in each situation. Does the outdoor temperature affect the amount of fuel needed to heat a house? Is there a relationship between people’s ages and their heights? Does the amount of rain in a region depend on its latitude?

Homework: Pg. 64 # 1, 3, 4 Compacting: Pg. 66 # 7, 8, 10