For each example below you would start to construct a confidence interval by identifying which distribution should be used to find the margin of error. it is possible that you won't be able to use either distribution. (a) a confidence interval for a population proportion where n = 30 and there are 18 successes in your sample leading to a sample proportion of 0.600 z-distribution t-distribution neither distribution (b) a confidence interval for a population proportion where n = 50 and there are 46 successes in your sample leading to a sample proportion of 0.920 z-distribution t-distribution neither distribution