Exam 2 - Statistics Flashcards
what measures the outcome of a study
response variable
what explains or causes changes in the response variables
explanatory variable
what kind of plot shows the relationship between two quantitative variables measured on the same individuals
scatterplot
when above-average values of one tend to accompany above-average values of the other and below-average values also tend to occur together
positive association
when above-average values of one tend to accompany below-average values of the other, and vice versa
negative
the direction and strength of the linear relationship between two quantitative variables
correlation
the magnitude of r
strength
if the correlation is zero, then the slop of the least-squares regression line is
zero
b1
slope
b0
intercept
what is the straight line formula
y(hat) = b0+b1x
a straight line where we have data on an explanatory variable and a response variable
least-squares regression line
slope’s equation
b1=rSy/Sx
intercept equation
b0=y-b1x
square of the correlation
r^2
the fraction of the variation in the values of y that is explained by the least-squares regression of y on x
r^2