Statistics

The Gallup Poll asks 1500 American residents age 18 or over, "If the election were held today, would you vote for the Republican candidate or the Democratic candidate for Congress in your district?" Based on the responses, 54% said "Republican," 34% said "Democratic," and 12% were undecided. (a) Is the value of 54% a parameter or a statistic? Explain. (b) If a large proportion of those polled refuse to answer the question, then this survey might be subject to bias