Answer:
a
    The population of interest is the registered voters , this is because  it is the population from which the sample size is selected from. 
b
The  population is the registered voters of the  large southwestern state 
c
Well this does not adequately represent the population because this sample where selected from only the registered voters of the  large southwestern state  and not the whole country 
d
    Yes the result will be nearly the same because 
-     Both samples are selected from the same population 
-     The size of the  sample selected is sufficiently large to approximate      the population 
Step-by-step explanation:
From the question we are told that 
    The sample size is  n =  5,500 
 Considering question a 
  What is the population of interest 
    The population of interest is the registered voters , this is because  it is the population from which the sample size is selected from. 
 Considering question b
 What is the population from which the sample was selected    
   The  population is the registered voters of the  large southwestern state   
 Considering question c
     Does the sample adequately represent the population
Well this does not adequately represent the population because this sample where selected from only the registered voters of the  large southwestern state  and not the whole country 
Considering question d
    Yes the result will be nearly the same because 
-     Both samples are selected from the same population 
-     The size of the  sample selected is sufficiently large to approximate      the population