Understanding Relationships in Scatter Plots, Lecture notes of Advanced Data Analysis

Download Understanding Relationships in Scatter Plots and more Lecture notes Advanced Data Analysis in PDF only on Docsity! Name ___________________________ Date __________________ Period_________ Relationships on a Scatter Plot Goals: Students will analyze scatter plots to determine: -Are variables X and Y related? -Are variables X and Y linearly related? If so How? -Does the variation in Y change depending on X? A scatter plot reveals relationships between two variables. Such relationships manifest themselves by any non-random structure in the plot. Various common types of relationships are demonstrated in the examples. Part I – Positive and Negative Positive relationship a clear line that goes up. Inverse or Negative relationship a line that goes down. No relationship no clear pattern, or line is perfectly horizontal or vertical The following are descriptions of slope of a line or pattern on a scatter plot. Identify the relationship that best fits each description. 1) Positive slope ____________________ 2) Negative slope ____________________ 3) -36.5 ____________________ 4) 0.0036 _____________________ 5) 23.6 _____________________ 6) _____________________ 7) In a positive relationship, if the X variable increases what happens to the Y variable? 8) In a negative relationship, if the X variable increases what happens to the Y variable? 9) State a general rule for using slope to determine the relationship on a scatter plot. ∞ Part II A scatter plot is a plot of the values of Y versus the corresponding values of X: - Vertical axis: variable Y--usually the dependent variable - Horizontal axis: variable X--usually the independent variable Strong relationship a clear line or predictable pattern. Weak relationship the line is there but it is “fuzzy” No relationship no clear pattern, or line is perfectly horizontal or vertical 10) Since graphs are scientific models and we use models to make predictions, then explain how strong and weak relationships affect the ability to make predictions. 11) If there is a strong positive relationship explain how the dependent variable changes with a change in the independent variable? 12) If there is no relationship explain how the dependent variable changes with a change in the independent variable? 13) In terms of the dependent and independent variable what does a shallow slope mean? 14) In terms of the dependent and independent variable what does a steep slope mean?