Answer:
11i-6
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
 
And if we solve for a we got
 
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.  
Step-by-step explanation:
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
 
  
Where  and
 and  
For this part we want to find a value a, such that we satisfy this condition:
 (a)
   (a)
 (b)
   (b)
As we can see on the figure attached the z value that satisfy the condition with 0.20 of the area on the left and 0.80 of the area on the right it's z=-0.842
If we use condition (b) from previous we have this:
 
  
 
But we know which value of z satisfy the previous equation so then we can do this:
 
And if we solve for a we got
 
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.  
 
        
             
        
        
        
Answer: 8/9
Step-by-step explanation: 0.888... can be simplified to 8/9.
 
        
             
        
        
        
Answer:
f(-3) =16
Step-by-step explanation:
f(x) = -5x + 1
f(-3) means let x=-3
Substituting x=-3 into the equation
f(-3) = -5 (-3) +1
Multiplying -5 and -3
f(-3) = 15+1
f(-3) =16
 
        
                    
             
        
        
        
I think it may be a polynomial of 11 terms (degree = 11)