Suppose that a survey is planned to estimate the proportion of a population that is left-handed. The sample data will be used to form a confidence interval. Explain which one of the following combinations of sample size and confidence level will give the widest interval.
(i) n = 400, confidence level = 90%.
(ii) n = 400, confidence level = 95%.
(iii) n = 1000, confidence level = 90%.
(iv) n = 1000, confidence level = 95%.