Please explain how these percentages were determined:

Assuming a surveyor reviewed 1,000 individuals and saw that 600 of them intended to decide in favor of Competitor A, the surveyor could be 95% certain that the genuine level of individuals who wanted to decide in favor of Up-and-comer A was somewhere in the range of 57% and 63%.

The number of respondents, the margin of error, the type of poll, and the pollster's accuracy all play a role in a poll's ability to accurately predict an outcome. The results will be more accurate the more people are surveyed, so the number of people surveyed is important. Because it measures the amount of variation in the results, the margin of error is crucial. Because different kinds of polls have different levels of accuracy, the type of poll matters. Because different pollsters have different levels of accuracy, the pollster's accuracy is important.