Before the Presidential Debates, It Was Expected That the Percentages

Essay

Before the presidential debates, it was expected that the percentages of registered voters in favor of various candidates would be as follows: $$\begin{array}{l}&\text { Percentages }\\\text { Democrats } & 48 \% \\\text { Republicans } & 38 \% \\\text { Independent } & 4 \% \\\text { Undecided } & 10 \%\end{array}$$ After the presidential debates, a random sample of 1200 voters showed that 540 favored the Democrat candidate; 480 were in favor of the Republican candidate; 40 were in favor of the Independent candidate, and 140 were undecided. At a 5% level of significance, carry out a test to determine if the proportion of voters has changed.