Part 1:
To calculate the probability of randomly selecting a person who will vote for Candidate 1 or 2, we add the number of supporters for Candidate 1 and Candidate 2 and divide by the total number of registered voters surveyed.
Probability = (250 + 1250) / 2500
Probability = 1500 / 2500
Probability = 0.6 or 60%
Therefore, the probability of randomly selecting a person who will vote for Candidate 1 or 2 is 60%.
Part 2:
If 1,000 more voters are surveyed, we can assume that the proportions of supporters for each candidate remain the same. We can calculate the number of voters who will likely prefer Candidate 3 or 4 by adding the number of supporters for Candidate 3 and Candidate 4 and then dividing by the total number of voters.
Number of voters supporting Candidate 3 or 4 = (450 + 550) / (2500 + 1000)
Number of voters supporting Candidate 3 or 4 = 1000 / 3500
Number of voters supporting Candidate 3 or 4 = 0.2857 or 28.57%
Therefore, if 1,000 more voters are surveyed, it is likely that 28.57% of them will prefer Candidate 3 or 4.