Recursive Formula
Explicit Formula
Residuals
Correlation Coefficient
Unit 3 Misc. Review
100
Sometimes sequences are described in subscript notation. What does a1 irepresent?
The first term in a sequence
100
The explicit formula for the arithmetic sequence: 2, 6, 10, 14, ...
an = 2 + 4(n-1)
or
an = 4n - 2
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
Write an recursive rule for the sequence 1, -2, -5, -8
an= an-1 -3 where a1=1
200
What is the explicit formula for the arithmetic sequence: -1, 2, 5, 8, 11
an = -1 + 3(n-1)
or
an = 3n - 4
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
Sometimes sequences are described in subscript notation. What does a1 represent?
The first term in a sequence.
300
Write a formula for the sequence 100, 97, 94, 91, ....
an= an-1 -3 where a1=100
300
The explicit formula for the sequence 3, 9, 15, 21, ...
an = 3 + 6(n-1)
or
an = 6n - 3
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
A sequence is defined by the recursive rule an=an-1 +4 a1=-8. Write the first five terms of the sequence.
-8, -4, 0, 4, 8
400
(-16, -25, -34, -43, -52) Formula: an = -16 - 9(n-1)
Find the value of a10
a10 = -97
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 common difference of the sequence represented in the table?
Time in minutes n: 2 4 6
Elevation of scuba diver in feet An: -4 -8 -12
-2
500
-100, -50, 0, 50,...
Write the explicit equation and find the 7th term.
an = -100 + 50(n-1) , a7 = 200
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