What is a multiple regression equation? (Select all that apply.) ...

[Arii_bell]

What is a multiple regression equation? (Select all that apply.)
 
  a. One that represents the mathematical effect that several independent variables have on the dependent variable
  b. One in which the x-values are multiplied by one another
  c. One that explains more of the variance in y than does a single linear regression equation
  d. An experimental model for determining best practices
  e. One that uses more than one predictor variable to predict the value of the outcome variable
  f. One that explains all of the variance in the dependent variable, in terms of several independent variables

Question 2

A researcher conducts research on optimism. The researcher is calculating a multiple regression equation to predict levels of optimism and wishes to consider religious affiliation as one of the predictor variables.
 
  The researcher creates several dummy variables for this purpose. Why must this be done? (Select all that apply.)
  a. It is safer to create more variables than fewer, since they may each contribute.
  b. Multiple regression requires that the researcher enter numerical values, not names such as Lutheran, Orthodox Jewish, Buddhist, Islamic, and so forth.
  c. Reducing nominal or categorical data to one or a series of dichotomous values allows mathematical computation of the regression equation.
  d. Religious affiliation is a protected entity under HIPAA and must be coded before it is used in calculations.
  e. The researcher's aim is to develop a formula with which to calculate optimism, given certain other variables, so these must all be represented as numbers.

[meganlapinski]

Answer to Question 1

ANS: A, C, E
Multiple regression is an extension of simple linear regression in which more than one independent variable is entered into the analysis. Because the relationships between multiple predictors and y are tested simultaneously, the calculations involved in multiple regression analysis are very complex. Multiple regression is best conducted using a statistical software package. A multiple regression formula explains some or all of the variance in the dependent variable; it cannot explain all of it.

Answer to Question 2

ANS: B, C, E
Variables in a regression equation can take many forms. Traditionally, as with most multivariate analyses, variables are measured at the interval or ratio level. However, researchers also use categorical or dichotomous variables, by assigning the terms numbers to represent them (referred to as dummy variables). These numbers are further converted to binary numbers; after this, they are entered one digit at a time as a series of dummy variables. For instance, if a nominal or categorical variable has two values, one dummy variable may be used (0, 1). If a nominal or categorical variable has three or four values, however, two different dummy variables are used to represent them. For five to eight values, three dummy variables are used, and so forth.

[Arii_bell]

Correct answers!

[meganlapinski]

Great! Please up vote