Answer:
 
And we can find this probability with the normal standard distirbution or excel and we got:
 
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  
Solution to the problem
Let X the random variable that represent the lenghts of a population, and for this case we know the distribution for X is given by:
 
  
Where  and
 and  
We are interested on this probability
 
And the best way to solve this problem is using the normal standard distribution and the z score given by:
 
If we apply this formula to our probability we got this:
 
And we can find this probability with the normal standard distirbution or excel and we got:
 
 
        
             
        
        
        
Answer:
khing chong
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x= 1 or x=7
Step-by-step explanation:
2 x 2− 16 x + 14 =0
2 (x−1) (x−7)=0
x−1=0  or  
x−7=0
x=1  or  x=7
 
        
                    
             
        
        
        
Answer:It should be D E F since they all are closer to 1
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x = 1 or x = 
Step-by-step explanation:
The expression inside the absolute value function can be positive or negative
That is 3x - 7 = ± 4
There are 2 equations to solve
(1)
3x - 7 = 4 ( add 7 to both sides )
3x = 11 ( divide both sides by 3 ) 
x = 
(2)
3x - 7 = - 4 ( add 7 to both sides )
3x = 3 ( divide both sides by 3 )
x = 1