Instruction: (The are 20 question to be answer for Module 5) sigma X = 11 sigma
ID: 3253610 • Letter: I
Question
Instruction: (The are 20 question to be answer for Module 5) sigma X = 11 sigma X^2 = 39 sigma Y = 22 sigma Y^2 140 sigma XY = 71 What is the predictor variable? What is the criterion variable? Compute the Pearson correlation. What is the covariance? What is the standard deviation of the predictor variable? What is the standard deviation of the criterion variable? What is the Pearsons r value? What is the best interpretation of your Pearson correlation in Q6? A. As hours studied' goes up there is a corresponding increase in score on quiz B. As hours studied* goes up there is a corresponding decrease in score on quiz' The strength of the above relationship is considered A. weak B. moderate C. strong Compute the regression equation. What is the numeric value for the slope? What is the y - intercept?Explanation / Answer
1) predictor variable - hours studied
The presumed “cause” on a nonexperimental study. Often used in correlational studies. For example, SAT scores predict first semester GPA. The SAT score is the predictor variable.
2) criterion variable - score on quiz
The presumed effect in a nonexperimental study
3)
covariance =
E(XY) - E(X)E(Y)
E(XY) = 71/4
E(X) = 11/4
E(Y) = 22/4
cov(X,Y) = 71/4 - 11*22/16 = 2.625
standard deviation of X = sqrt ( E(X^2) - E(X)^2)) = sqrt( 1/4*(39 )-11^2/16) =1.4790
standard deviation of Y = sqrt( 140/16 - 22/4 ) = 1.8027
correlation = 2.625 / (1.479 * 1.8027 ) =0.984549