The population proportion of success is 8% and the intended sample size is n=824. before drawing a sample from the population, you first want to estimate the 85-th percentile, that is the value separating the lower 85% of the sample proportions from the upper 15% of the sample proportions. for this problem, the normal approximation will be used. first, it is necessary to calculate the "critical value", which is the z-score separating the lower 85% of the standard normal distribution from the upper 15%: zc. v.= for the sample proportions: p85= answers in decimal format (as opposed to fractions or percentages).