Causing Problems
"The more I eat, the more weight I gain"
Is this an example of correlation or causation?
Causation
What do you call a clump of points, oftentimes not following the path of the line of fit?
A cluster.
What do you call a point that is far from the other points on a scatterplot?
Outlier
Mr. Coffey notices that students with brown eyes tend to score higher on tests.
Is this an example of correlation or causation?
Correlation
Which represents the best line of fit for the scatterplot? See ppt slide 43.
y = -0.7x + 6.7
Where can you find a negative residual?
Under the line of fit
Approximate the value of x when y = 4. See slide 46.
x = -4
If two variables are correlated, do they always have a causation relationship?
No
A line of best fit is given by the equation y = 1.1x + 4.
If x represents the hours practicing basketball and y represents the score, interpret the meaning of the slope.
The score increases by 1.1 per hour of practice.
Sort the residuals into positive and negative groups. See PPT slide 45.
A and F are positive
B, C, D, and E are negative
Approximate the value of y when x = -6. See slide 46.
y = 5
Which pair most likely shows a correlation but NOT a causation?
Practicing basketball and drinking more water.
Practicing basketball and better basketball skills.
Practicing basketball and improved endurance.
Practicing basketball and drinking more water
A line of best fit equation is given by y = 2.5x + 1
If x represents the hours of sleep, and y represents a test score, interpret the meaning of the y-intercept in the equation.
Describe the direction and strength of a correlation coefficient of -0.3.
Based on the trend of the data, what grade is a student who studies for 36 minutes likely to receive? See PPT slide 47.
75
Give your own example of a causation relationship between two variables.
Varies
Which line of best fit equation best fits the model in the picture? Slide 44.
y = -0.8x + 9
Order the correlation coefficients from strongest to weakest:
-0.3, 0.99, -1, 0.24
-1, 0.99, -0.3, 0.24
Based on the trend of the data, how much study time would it take for a student to receive a grade of 85?
50 minutes