Final answer:
Several nonsampling errors including interviewer error, data-entry error, nonresponse bias, and selection bias led to the incorrect prediction of an election outcome.
Step-by-step explanation:
Given the situation described, where pollsters incorrectly predicted the winner of an election in a particular region, there are several nonsampling errors that led to the incorrect conclusion. Firstly, there was an interviewer error because the young interviewers may have caused nonresponses from groups other than young voters, who were more likely to prefer Candidate A, leading to a nonresponse bias. Secondly, a data-entry error occurred because some responses were lost due to computer issues, potentially skewing the results towards one candidate. Lastly, the method of selecting individuals led to a lower proportion of female voters being interviewed, and since Candidate B was favored by females, this resulted in a selection bias. These issues are examples of nonsampling errors that contributed to the inaccurate prediction of the election result.