Linear Models (Equations)
Residuals
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
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
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
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
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
What TWO things does the correlation coefficient tell you about a relationship?
The strength and direction