Two Variable Statistics
Unit Description
In this unit, students will learn the distinction between categorical and quantitative data, distinguish between when to use a linear model and when to use an exponential model, use twoway frequency tables for displaying and analyzing categorical data, use and analyze linear functions when modeling situations with a constant rate of change per unit interval, use and analyze exponential functions when modeling situations with a constant percent rate per unit interval, use mathematical models to make predictions, and know that correlation does not imply causation.
Unit Skills
By the end of this unit, students will be able to:  Distinguish between categorical and quantitative data
 Summarize categorical data by constructing a twoway frequency table
 State a hypothesis that can be addressed by the collected data.
 Calculate and interpret joint frequencies, marginal frequencies, and conditional frequencies based on a two way table.
 Recognize possible associations and trends in categorical data by looking at a two way table.
 Create a scatter plot when given two quantitative variables
 Determine the type of function (linear or exponential) that best fits the data
 Recognize linear and exponential functions numerically, graphically, algebraically, and descriptively.
 Fit an appropriate function to data
 Interpret the constants and coefficients of a calculated function in context of the problem
 Use the fitted function to make predictions and solve problems
 Calculate the residuals for each data point that has been fitted to a function
 Create and analyze a residual plot
 Predict the strength and direction(+/) of the correlation coefficient from a scatter plot
 Utilize technology to compute and interpret the correlation coefficient
 Distinguish between correlation and causation of independent and dependent variables in a given context
 Identify possible extraneous variables in a given context
