Line of best fit
Outliers and Predictions
100
True of False:
Your line of best fit must go through at least 1 data point
False
100
When most of the points are close to the line of best fit, but one is very far, this is called an _______________.
Outlier
200
True or False:
There should be an equal number of points above and below the line.
True
200
True or False:
A line of best fit can go through an outlier
False
300
What are two points on the line of best fit? 
(0.2,15) (0.4,13) (0.6,14) (0.8,12) (1,13)
300
What are the coordinates of the outlier in this graph? 
(8.2,0.9)
400
What could be the equation of the line of best fit: A) y = 2x + 20 B) y = -2x + 20
C) y = -1/2 x + 20 D) y = -2x - 20
B) y = -2x + 20
400
The equation of the line of best fit is y = -2x + 15, where x represents the age of an infant, and y represents the hours of sleep the infant needs. Predict how many hours of sleep an infant who is 1 year old needs.
y = -2(1) + 15 = -2 + 15 = 13 hours
500
If there is no correlation, does the line have a positive or negative slope?
Neither! There is no line!
500
The equation of the line of best fit for a scatter plot is y = 12x - 200, where x represents the temperature outside and y represents the sales of the ice cream shop. Predict the sale of ice cream if the temperature is 80 degrees.
y = 12(80) - 216 = 960 - 200 = 760 so $760