Answer:
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%28%5Csum%20x%29%28%5Csum%20y%29%7D%7B%5Csqrt%7B%5Bn%5Csum%20x%5E2%20-%28%5Csum%20x%29%5E2%5D%5Bn%5Csum%20y%5E2%20-%28%5Csum%20y%29%5E2%5D%7D%7D) 
  
For this case the value of r = -0.66
Now we can calculate the determination coeffcient:

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable
And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable
Step-by-step explanation:
For this case we need to calculate the slope with the following formula:
 
Where:
 
 
 
 
And we can find the intercept using this:
 
And the model obtained for this case is:

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.
And in order to calculate the correlation coefficient we can use this formula:  
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%28%5Csum%20x%29%28%5Csum%20y%29%7D%7B%5Csqrt%7B%5Bn%5Csum%20x%5E2%20-%28%5Csum%20x%29%5E2%5D%5Bn%5Csum%20y%5E2%20-%28%5Csum%20y%29%5E2%5D%7D%7D) 
  
For this case the value of r = -0.66
Now we can calculate the determination coeffcient:

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable
And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable
 
        
             
        
        
        
Factors are: 0, 1, 2, 4, 8, 16
        
                    
             
        
        
        
Answer:
The discount is $0.8d.
Step-by-step explanation:
Given that,
The original cost of Tamara's purchase is d dollars.
Tamara uses a coupon to save 20% off her purchase at the bookstore.
Discount = 20%
Discount is applied to the original cost.
Discount = d-(20/100)d
Discount = 0.8 d
Hence, the discount is $0.8d.
 
        
             
        
        
        
Answer:
$3750
Step-by-step explanation:
Amount = principal + interest
Simple interest = Principal *Rate * time/100
Simple interest = 2500*10*5/100
Simple interest  = 25*50
Simple interest = $1250
Amount = $2500+$1250
Amount after 5 years is $3750
 
        
             
        
        
        
Answer: x=4. PS=QR=15
Step-by-step explanation: