Answer:
d) Squared differences between actual and predicted Y values.
Step-by-step explanation:
Regression is called "least squares" regression line. The line takes the form = a + b*X where a and b are both constants. Value of Y and X is specific value of independent variable.Such formula could be used to generate values of given value X.
For example,
 suppose a = 10 and b = 7. If X is 10, then  predicted value for Y of 45 (from 10 + 5*7). It turns out that with any two variables X and Y. In other words, there exists one formula that will produce the best, or most accurate predictions for Y given X. Any other equation would not fit as well and would predict Y with more error. That equation is called the least squares regression equation.
It minimize the squared difference between actual and predicted value.
 
        
             
        
        
        
$18.00 total payment
$15.00 x .05(tax) =$  .75
$15.00 x .15(tip) =$ 2.25
________________________
                             $ 3.00
                       +    $15.00
----------------------------------
                             $18.00
        
             
        
        
        
Answer:
The variance is direct. 
Step-by-step explanation:
Since size of the pizza determines the amount of calories. 
Let us say that a 2" x4" strip of pizza has 250 calories. 
Then a pizza of twice the size (or 4" x 4") will have twice as many calories (500 calories) . 
 
        
             
        
        
        
The radius of the circle is 1km