Week 3 Notes

Question 1

correlation and regression analysis

Answer 1

used to study the relationship between two variables

Question 2

correlation analysis

Answer 2

a group of techniques to measure association btwn two variables

Question 3

scatter diagram

Answer 3

one way of looking at the relationship between to variables
- a chart that portrays the relationship between two variables

Question 4

independent variable

Answer 4

explanatory or predictor variable (X-axis)
- provides the basis for estimation
- predictor variable

Question 5

dependent variable

Answer 5

response variable on the Y-axis
- variable that is being predicted or estimated

Question 6

coefficient of correlation

Answer 6

measure of the linear strength of the relationship between two sets of interval-scaled or ratio-scaled variables
- AKA Pearson’s product moment correlation coefficient
- AKA Pearson’s r
- value may range from - 1.00 to +1.00 (perfect negative to positive correlation)

Question 7

correlation in excel

Answer 7

=CORREL (highlight X values, highlight Y values) Press ENTER

Question 8

coefficient of determination

Answer 8

r^2
- reports the strength of the association
- has a range of 0.00 - 1.00 (%100)

Question 9

regression equation

Answer 9

an equation that defines the linear relationship between two variables
- used to estimate Y based on X

Question 10

least squares principle

Answer 10

minimizing sum of the squares of the vertical distances (residual or error) btwn that actual Y values & predicted values of y

Question 11

residual values

Answer 11

= observed value - predicted value

Question 12

Least squares regression line

Answer 12

line that minimizes sum of the squared errors (or residuals)

Question 13

multiple regression

Answer 13

set of techniques used to analyze the relationship between two or more independent variables and a dependent variable