select the three main reasons mentioned in the problem that helped determine the correct formula. The problem asks us to find (estimate) the confidence interval of the difference of proportions (p - p). The problem asks us to find (estimate) the confidence interval of the difference of means ( - ). The problem asks us to find (estimate) the confidence interval of population (true) mean (). The problem asks us to find (estimate) the confidence interval of the population (true) proportion (p). Asks us to find the sample size (how large or how many) The problem provides information on two samples. The problem provides information on one sample. The sample standard deviations are given or need to be calculated The population standard deviations are given