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.

Question

Quizplus · Accepted Answer

The Answer of 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.

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