Answer:
a) 
And we can find this probability with the complement rule:
b) 
And if we use the z score we got:
 
Step-by-step explanation:
Let X the random variable that represent the lengths of a population, and for this case we know the distribution for X is given by:
  
Where 
 and 
Part a
We are interested on this probability
And we can use the z score formula given by:
And using this formula we got:
And we can find this probability with the complement rule:
Part b
For this case we select a sample of n =44 and the new z score formula is given by:

And if we find the z score we got:

And if we use the z score we got:
 
 
        
             
        
        
        
A repeating decimal can be written like this
 
        
             
        
        
        
The answer I got to this was 2.3 but I don't know if that's correct. 
        
             
        
        
        
3. 3/10 and 5/10 4. 12/20 and 15/20 5.4/8 and 7/8 6. 8/12 and 5/12 7. 3/12 and 2/12. 8. 1/2>2/5 9.1/2 = 3/6 10. 3/4<5/6 11. 6/10=3/5