We polled a sample of 900 random people on whether they thought a candidate for a high government position deserves to be nominated. We found that 405 of the 900 people (or 45%) believe the candidate should not be nominated. What is the 95% confidence interval of the proportion of people not in favor of the nomination.
- 45% ± 1.96 * Sqrt(0.45*0.55/400)
- 45% ± 1.96 * Sqrt(0.45*0.55/20)
- 45% ± 1.65 * Sqrt(0.45*0.55/400)
- Not sufficient information to answer this question
We want to poll a sample of random people on whether they thought a candidate for a high government position deserves to be nominated. Suppose roughly 45% of the population is not in favor of the nomination. If we want to construct a 95% confidence interval and we want our margin of error to be no more than 2%, what should be our sample size?
- 450
- (1.96)^2*(0.45*0.55)/(2^2)
- (1.96)^2*(0.45*0.55)/(0.02^2)
- Cannot be answered from the information given.