UNIT 3 BIVARIATE DATA

Question 1

influential point

Answer 1

data point in a scatterplot that greatly affects the position/slope of the regression line
› can be an outlier as well
› may or may not be apart of the linear pattern of the data
› may strengthen or weaken correlation

Question 2

outlier

Answer 2

a data point that lies an abnormal distance from other values in a random sample
› affects the data but not dramatically
› removal of an outlier almost always strengthens correlation- outliers can decrease correlation coefficient
› x outlier will make the scope of the regression too broad which is considered less accurate

Question 3

residual

Answer 3

the difference between the actual value of a dependent variable (y) and the predicted value of that variable based on a regression line

Question 4

high leverage point

Answer 4

data point in a regression line that has an extreme value on the independent variable (x axis)
› sits farther away from the other data points on the x axis
› potentially causes a significant impact on the regression line

Question 5

low leverage point

Answer 5

data point in a regression line that has an x value very close to majority of other data points
› does not have a significant influence on the position of the regression line

Question 6

leverage