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Linear Equation
Slope
Y-intercept
Associations
100
What is the equation for linear regression?
y-hat = b0 + b1*x
100
In statistics, this is the symbol for the slope.
What is b1?
100
In statistics, this is the symbol for the y-intercept.
What is b0?
100

What is a positive association?

As one variable increases, the other variable increases.

200
Predicted Price = 18.617 + 103.929 Capacity. This is the regression equation for disk space Capacity (in megabytes) versus Price at a local store. With a capacity of 2 mb, what would you expect the price to be?
$226.475
200
This is the equation for the slope in statistics.
What is Average Y - b1*Average X?
200
This is the equation for the y-intercept in statistics.
What is r*(Sy/Sx)
200

What is a negative association?

As one variable increases, the other variable decreases.

300
You are given r = 0.45, Sy = 28 and Sx = 54. What is the slope?
0.2333
300
The linear model for a local store's Number of Sales people working versus Sales is as follows: Sales = 8,106 + 91.34Number of Sales People Working. What is the y-intercept?
$8,106
300

What is the difference between no association and nonlinear association?

No association means there is no relationship between the two variables. Nonlinear association means that we cannot draw a straight line through the data, however, there could still be a relationships between the two variables.

400
The linear model for a local store's Number of Sales people working versus Sales is as follows: Sales = 8,106 + 91.34Number of Sales People Working. With 14 people working, what would you expect sales to be?
$9,384.76
400
Predicted Price = 18.617 + 103.929 Capacity. This is the regression equation for disk space Capacity (in megabytes) versus Price (in dollars) at a local store. What does the slope of 103.929 mean in this context?
For every 1 mb increase in capacity, the price increases by $103.929.
400
Predicted Price = 18.617 + 103.929 Capacity. This is the regression equation for disk space Capacity versus Price at a local store. Does the y-intercept have meaning?
No, no one would buy a disk with zero capacity.
500
An analysis of Math SAT versus Verbal SAT scores gives an equation of Predicted Verbal SAT Score = 171.333 + 0.6943Math SAT Score. What would you predict someone's verbal score to be if they got a 520 on their Math section?
532.369
500
The linear model for a local store's Number of Sales people working versus Sales is as follows: Sales = 8,106 + 91.34Number of Sales People Working. What does the slope mean in this situation?
For every increase of 1 sales person working, sales increase by $91.34.
500
The linear model for a local store's Number of Sales people working versus Sales is as follows: Sales = 8,106 + 91.34Number of Sales People Working. Does the y-intercept have meaning in this equation?
No, when no one is working, there should be no sales. This is just a starting point for the data.