Final answer:
Averaging poll results is reasonable because it mitigates individual poll biases, creating a more accurate representation of public sentiment. Polls use random sampling and seek an optimal balance between sample size and cost, with adequate sample sizes delivering reliable results with an acceptable margin of error.
Step-by-step explanation:
Averaging a number of poll results is a reasonable approach because it helps reduce individual poll biases and errors, leading to a more stable estimate that is likely closer to the true sentiment of the entire population. When multiple polls are averaged, the unique errors or biases of each poll are likely to cancel out, assuming they are random and not systematic. This is why poll aggregators often provide a clearer picture of public opinion than any single poll. Consider this: Polling is a method to gauge public opinion by taking a sample of the population. If done correctly using random sampling, a poll can statistically represent the viewpoints of a much larger group. Since obtaining a complete view of the population is typically not feasible due to practical constraints such as time and resources, averaging polls becomes useful. The larger the sample size and the more random and representative it is, the more accurate the poll will be. However, beyond a certain point, increasing the sample size yields diminishing returns; hence pollsters strive to find an optimal balance between sample size and cost.