X-12 -8 
calculate the difference
X-20
        
             
        
        
        
I FOUND YOUR COMPLETE QUESTION IN OTHER SOURCES.
 PLEASE SEE ATTACHED IMAGE.
 First, we define the variables: 
 x: number of years after 1950
 f (x): amount of vinyl sold.
 Then, with the variables defined, we have:
 68594 vinyl records were sold in 1958 ---------> f (8) = 68594
 91299 vinyl records were sold in 1961 ---------> f (11) = 91299
 38720 vinyl records were sold in 1952 ---------> f (2) = 38720
 161743 vinyl records were sold in 1967 ---------> f (17) = 161743
 
        
             
        
        
        
Answer:
c) 
Step-by-step explanation:
 Equation for regression line of y on x is given as

where 
 = predicted value
 = predicted value
m = slope of line
b = intercept
m and b are found as

r = correlation coefficient = 0.88
Sx = standard deviation for independent variable x = 13
Sy = standard deviation for dependent variable y = 27
 = mean value of independent variable x = 21
 = mean value of independent variable x = 21
 = mean value of dependent variable y = 55
 = mean value of dependent variable y = 55
Substituting these values in (2) and (3)


Putting these values of m and b in (1)

 
        
             
        
        
        
Answer:
x = 0.8
Step-by-step explanation:
For this problem we will be using trigonometry :