Statistics Sophia 4

Statistics Sophia 4 scatterplot - ANSWERSA graphical display that allows us to see the relationship between two quantitative variables. multiple data sets - ANSWERSPlotting more than one data set on a scatterplot requires that we use different colors or symbols for the different data sets so we can see the relationships separately. form - ANSWERSThe overall shape of the data points. The form may be linear or nonlinear, or there may not be any form at all to the points if they form a "cloud." direction - ANSWERSThe way one variable responds to an increase in the other. With a negative association, an increase in one variable is associated with a decrease in the other, whereas with a positive association, an increase in one variable is associated with an increase in the other. strength - ANSWERSThe closeness of the points to the indicated form. Points that are strongly linear will all fall on or near a straight line. explanatory variable - ANSWERSThe variable whose increase or decrease we believe helps explain a tendency to increase or decrease in some other variable. response variable - ANSWERSThe variable that tends to increase or decrease due to an increase or decrease in the explanatory variable. correlation - ANSWERSThe strength and direction of a linear association between two quantitative variables. correlation coefficient - ANSWERSThe numerical value between -1 and +1 that measures the correlation between two quantitative variables. positive correlation - ANSWERSThe type of correlation present when two variables have a correlation coefficient generally greater than or equal to 0.5. negative correlation - ANSWERSThe type of correlation present when two variables have a correlation coefficient generally less than or equal to -0.5. Relative Zero Correlation - ANSWERSThe type of correlation present when two variables have a correlation coefficient generally between -0.5 and 0.5. non-linear relationships - ANSWERSAssociations between two variables that can be modeled better with a curve than a line. Coefficient of Determination (r^2) - ANSWERSA value that explains the percent of variation in the response variable that can be explained by a linear association with the explanatory variable. It is the square of the correlation coefficient. finding r from r squared - ANSWERSStep 1: Take the square root of r2. If only rsquared is given, what you have to do is take the square root to obtain the correlation coefficient, r.