A proposal for a new 1-cent tax increase to support cancer research is to appear on the ballot in one county's next election. The residents in two cities were questioned as to their level of support. In Sterling Heights a recent survey of 225 residents showed that 140 people supported the proposal, 35 were undecided, and the remainder were opposed to the new proposal. In a nearby community, Harrison Township, the results of a random sample of 210 residents found that 120 people supported the tax, 30 were opposed, and the remainder were undecided. Estimate the difference in the percentages of residents from these two communities who support this proposal. Use a 95% confidence level.