In the last presidential election before the candidates began their major campaigns

Question

In the last presidential election before the candidates began their major campaigns, the percentages of registered voters who favored the various candidates were as follows.

	Percentage
Republicans	34
Democrats	43
Independents	23

After the major campaigns began, a random sample of 400 voters showed that 172 favored the Republican candidate; 164 were in favor of the Democratic candidate; and 64 favored the Independent candidate. Test with a= .01 to see if the proportion of voters who favored the various candidates changed.