click below
click below
Normal Size Small Size show me how
STAT chapt 3
| Question | Answer |
|---|---|
| cross–tabulation table | an arrangement of data in a two–way classification. |
| input variable | the variable we know or can control. |
| least squares criterion | requires finding the constants b0 (y–intercept) and b1 (slope) such that the sum of the squares of observed minus predicted values is as small as possible. |
| line of best fit | a line whose equation represents the smallest possible differences between the squares of observed minus predicted values on a line |
| linear correlation | the strength of a linear relationship between two variables, determined by the preciseness of shift in y as x increases. |
| linear regression | the straight line that best describes the relationship between two variables |
| lurking variable | a variable that is not included in a study but has an effect on the variables of the study and makes it appear that those variables are related. |
| negative correlation | a correlation in which an increase in x leads to a decrease in y. |
| ordered pairs | a mathematical expression (x, y) where x is the input variable written first, and y is the output variable written second. |
| output (dependent) variable | the predicted variable. |
| Pearson’s product moment formula | the formula that determines the coefficient of linear correlation (r). |
| positive correlation | a correlation in which an increase in x leads to an increase in y. |
| predicted value | the value of y calculated by modeling a particular value of x with a prediction equation. |
| prediction equation | an equation that models a mathematical relationship between x and y with an algebraic expression. Examples of prediction equations include linear (straight–line), quadratic, exponential, and logarithmic. |
| regression | the algebraic expression that describes the relationship between two variables |
| regression analysis | finds the equation of the line that best describes the relationship between the two variables under examination. That is, regression analysis describes the mathematical relationship between the two variables. |
| scatter diagram | a plot of all the ordered pairs of bivariate data on a coordinate axis system. |
| slope, b1 | the ratio of the rise over the run (horizontal distance) of a line. In the equation for a line of best fit, the slope is denoted b1. |