Answer: To find the approximate number of voters who are undecided about the candidates for mayor, we can first add up the percentages of voters who have already made their decision:
14 + 31 + 39 = 84%
This means that 84% of the voters have made up their minds about the candidates. To find the percentage of voters who are undecided, we can subtract this percentage from 100:
100 - 84 = 16%
So approximately 16% of the 2,500 voters in Newtville would be undecided about the candidates for mayor. To find the number of voters who are undecided, we can multiply the total number of voters by the percentage that is undecided:
2,500 x 0.16 = 400
Therefore, approximately 400 voters in Newtville would be undecided about the candidates for mayor.