Term

Definition
values of two different variables that are obtained from the same population element. 


Term
BIVARIATE2 qualitative variables 

Definition


Term
BIVARIATE 1 Qualitative, 1 Quantitative 

Definition
displayed sidebyside as separate samples to compare 


Term
BIVARIATE 2 Quanitative 

Definition
displayed as ordered pairs(x,y) x=input (independent); y=output (dependent) 


Term

Definition
plot of all ordered pairs of bivariate data on coordinate axis (x=horizontal, y=vertical) 


Term

Definition
measures strength of linear relationship between two variables. 


Term

Definition
as x increases, there is no shift in y values 


Term

Definition
y increases as x increases 


Term

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(xxbar)(yybar)]/[(n1)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

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

Definition
relationship between two variables as an algebraic expression describing the mathematical relationship between x and y
 linear: y=b_{0} + b_{1}x
 quadratic: y=a + bx+cx^{2}
 exponential: y = a(b^{x})
 logarithmic: y=alog_{b}x



Term

Definition
slope = B1
B_{1}=(Σ(xxbar)(yybar))/Σ(xxbar)^{2}
B_{1}= SS(xy)/SS(x) 


Term

Definition
yintercept = B_{0}
B_{0}=(Σy(b1*Σx))/n
B_{0}=ybar(B_{1}*xbar) 

