Answer:
2
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
x = (b-c)/a
Step-by-step explanation:
ax + b = c
Subtract b from each side
ax+b-b = c-b
ax = b-c
Divide by a
ax/a = (b-c)/a
x = (b-c)/a
 
        
                    
             
        
        
        
Answer: 3.712 hours or more
Step-by-step explanation:
Let X be the random variable that denotes the time required to complete a product.
X is normally distributed.

 Let x be the times it takes to complete a random unit in order to be in the top 10% (right tail) of the time distribution.
Then, 
![P(z>\dfrac{x-3.2}{\sigma})=0.10\ \ \ [z=\dfrac{x-\mu}{\sigma}]](https://tex.z-dn.net/?f=P%28z%3E%5Cdfrac%7Bx-3.2%7D%7B%5Csigma%7D%29%3D0.10%5C%20%5C%20%5C%20%5Bz%3D%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%5D)
As,  [By z-table]
  [By z-table]
Then, 

So, it will take 3.712 hours or more to complete a random unit in order to be in the top 10% (right tail) of the time distribution.