A choral conductor has 1955 singers in her choir, some of them are professional singers. The conductor wants to estimate what percentage of singers are professional, but can't ask all 1955, so she instead asks 654 singers in front and finds 18 who are professionals.

(a) Identify the parameter

A. 18
B. range of values in which 95% values fall
C. percentage of entire singers who are professional
D. None of the above.

(b) Identify the sample.

A. 18/1955
B. singers who were asked
C. 654
D. None of the above.

(c) Identify the population

A. percentage of entire singers who are professional
B. entire singers
C. 18/1955
D. None of the above.

(d) What specific type of bias does this scenario demonstrate?

A. Convenience Sampling
B. Voluntary response sampling
C. It is representative of the population.
D. None of the above.