Page 12 - Statistics II for Dummies

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Statistics II For Dummies
Just Like Buying Shoes: The Model Looks Nice, But Does It Fit? ..........109
Assessing the fit of multiple regression models ............................110

Model selection procedures .............................................................111
Chapter 7: Getting Ahead of the Learning Curve
with Nonlinear Regression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Anticipating Nonlinear Regression ............................................................116
Starting Out with Scatterplots ...................................................................117
Handling Curves in the Road with Polynomials ......................................119
Bringing back polynomials ...............................................................119
Searching for the best polynomial model .......................................122
Using a second-degree polynomial to pass the quiz .....................123

Assessing the fit of a polynomial model .........................................126
Making predictions ............................................................................129
Going Up? Going Down? Go Exponential! .................................................130
Recollecting exponential models .....................................................130
Searching for the best exponential model ......................................131
Spreading secrets at an exponential rate .......................................133

Chapter 8: Yes, No, Maybe So: Making Predictions
by Using Logistic Regression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137

Understanding a Logistic Regression Model ............................................138
How is logistic regression different from other regressions? ......138
Using an S-curve to estimate probabilities .....................................139
Interpreting the coefficients of the logistic regression model .....140

The logistic regression model in action ..........................................141
Carrying Out a Logistic Regression Analysis ...........................................142
Running the analysis in Minitab .......................................................142
Finding the coefficients and making the model .............................144

Estimating p ........................................................................................145

Checking the fit of the model ...........................................................146
Fitting the Movie Model ....................................................................147

Part III: Analyzing Variance with ANOVA .................. 151

Chapter 9: Testing Lots of Means? Come On Over to ANOVA!. . . . . .153
Comparing Two Means with a t-Test ........................................................154
Evaluating More Means with ANOVA ........................................................155
Spitting seeds: A situation just waiting for ANOVA .......................155
Walking through the steps of ANOVA .............................................156
Checking the Conditions .............................................................................157
Verifying independence ....................................................................157
Looking for what’s normal ................................................................158
Taking note of spread ........................................................................159
Setting Up the Hypotheses .........................................................................162

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