The percent of variation is 85.1%.  If you enter the numbers into a calculator and store the regression equation, it will be the r^2 value when calculated.
        
             
        
        
        
Answer:

Step-by-step explanation:
To find the distance between any two points, we can use the distance formula: 

Our first point, A, is at (1, 1) and our second point, B, is at (-2, 8). 
Let's let A(1, 1) be (x₁, y₁) and B(-2, 8) be (x₂, y₂). Substitute this into the distance formula: 

Subtract: 

Square: 

Add: 

This cannot be simplified. 
So, the distance between the two points is √58 or about 7.6 units. 
And we're done!
So... where's my cookie :)? 
 
        
             
        
        
        
The Pythagorean Theorem states that a² + b² = c², c being the hypotenuse.
Substitute known values into the equation.
7² + 2² = c²
49 + 4 = c²
c² = 53
c = √53
c = 7.28010989
Answer: The hypotenuse's length is 7.3 feet.
        
             
        
        
        
20100 = 16000 * (1.02)^ t
20100/16000 = 1.02^t
1.25625 = 1.02^t
log 1.25625 = t * log 1.02
t = log 1.25625 / log 1.02
 = 11.5