# Shared Flashcard Set

## Details

Statistics-MU
Chapter 3
18
Mathematics
09/19/2012

Term
 Bivariate Data
Definition
 values of two different variables that are obtained from the same population element.
Term
 BIVARIATE--2 qualitative variables
Definition
 cross-tabulation table
Term
 BIVARIATE-- 1 Qualitative, 1 Quantitative
Definition
 displayed side-by-side as separate samples to compare
Term
 BIVARIATE-- 2 Quanitative
Definition
 displayed as ordered pairs(x,y) x=input (independent); y=output (dependent)
Term
 Scatter Diagram
Definition
 plot of all ordered pairs of bivariate data on coordinate axis (x=horizontal, y=vertical)
Term
 linear correlation
Definition
 measures strength of linear relationship between two variables.
Term
 No correlation
Definition
 as x increases, there is no shift in y values
Term
 positive correlation
Definition
 y increases as x increases
Term
 Negative Correlation
Definition
 y decreases as x increases
Term
 coefficient of linear correlation
Definition
 numerical measure of strength of the linear relationship between two variables. (reflects consistency of the effect that a change has on the other)
Term
 Coefficient of Linear Correlation (Standards)
Definition
 ---r, between -1 (negative correlation) and +1 (positive correlation).---closer r is to 0, less correlated
Term
 Pearson's Product Moment Definition Formula
Definition
 Definition: R=[Σ(x-xbar)(y-ybar)]/[(n-1)sxsy]
Term
 Pearson's Product Moment Computational Formula
Definition
 Sum of Squares for xy divided by the squae root of the sum of squares for x multiplied by the sum of squares for y R = SS(xy)/√SS(x)SS(y) SS(x)= Σx^2-((Σx)^2/n) SS(y)= Σy^2-((Σy)^2/n) SS(xy)= Σxy-((ΣxΣy)/n)
Term
 Lurking Variable
Definition
 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.   ex) relationship shown between the amount of damage caused by a fire and the number of firefighters who work. Size of fire = lurking variable (effects both)
Term
 strong linear correlation
Definition
 one of the following may be true: direct cause and effect relationship between the two variables reverse cause and effect relationship between the two relationship may be caused by a third variable  may be caused by the interactions of several other variables the apparent relationship may be strictly coincidence
Term
 Models
Definition
 relationship between two variables as an algebraic expression describing the mathematical relationship between x and y linear: y=b0 + b1x quadratic: y=a + bx+cx2 exponential: y = a(bx) logarithmic: y=alogbx
Term
 Slope
Definition
 slope = B1 B1=(Σ(x-xbar)(y-ybar))/Σ(x-xbar)2 B1= SS(xy)/SS(x)
Term
 y-intercept
Definition
 y-intercept = B0 B0=(Σy-(b1*Σx))/n B0=ybar-(B1*xbar)
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