For a Given Level of Precision and Confidence Level, a Researcher

Multiple Choice

For a given level of precision and confidence level, a researcher determines that he needs a sample size of 400. The study found that the proportion of people who smoke is 30 percent. For the same level of precision and confidence, he would need the same sample size if the proportion of those who smoke were to change to:

A) 40 percent.
B) 50 percent.
C) 60 percent.
D) 70 percent.
E) 100 percent.