Linear Models (Equations)
Residuals
Correlation Coefficient
Unit 3 Misc. Review
100
Given the scatter plot and the equation, what does the y-intercept mean in this context?
The amount of battery life before spending any time on phone
100
How do you determine the value of a residual?
actual value - estimated value = residual
100
What is the range of the correlation coefficient?
-1 to 1
100
Given the line of best fit y = 2x + 4, find the estimated y for the point (5,6)
y= 14
200
Given the scatter plot and the linear equation, what does the slope mean in this context?
As the time spent on the phone increases by 1 hour, the amount of battery life decrease by 3/4 of an hour.
200
How do you determine the estimated value?
Use the equation for the line of best fit
200
-1 as a correlation coefficient indicates what kind of association?
Very strong negative (downhill)
200
What is slope-intercept form?
y = mx + b
300
Is the following the best fit, good fit, bad fit?Explain.
Best fit, line is through the middle of the data
300
An actual value is given in a scatter plot as (5, -11.5). An equation for a linear model is y=-3x + 2.5. What is the residual for this point?
1
300
0 as a correlation coefficient indicates what kind of association?
No association
300
If both variables increase together, what kind of association will be shown on a scatterplot?
Positive association
400
Which graph shows the most accurate line of best fit?
A
400
The actual value of a point is (1,2), the best fit equation is y=2x+1/2
Is the residual positive or negative?
Negative
400
0.5, 0, -0.72, 0.92
0.92, strong positive correlation
400
True or False: All residuals should be positive.
False. There should a nearly even split of positive and negative residuals for a good line of best fit
500
What is the equation for the line of best fit?
y=3/4x+1
500
A residual plot shows what about a linear model?
Whether a linear model is appropriate and the accuracy of the actual value to the estimated value. Smaller residuals indicate more accuracy
500
Draw an example of a scatterplot that would have a correlation coefficient of 0.
500
What TWO things does the correlation coefficient tell you about a relationship?
The strength and direction