(35 points) a catalogue ordering operation maintains an ordering staff of 25 telephone operators, who take orders from customers. management wants to determine the proportion of time that operators are idle. a work sampling study was conducted at random over a four-day period, and the following random observations were recorded: a) if management wants the proportion of time from the work sampling study to be 4% accurate with a confidence level of 98%, how many additional sample observations should be taken? b) after half of the observations (calculated on part a), the proportion of operators idle is 25%. to maintain the same confidence interval and accuracy, how many additional observations are needed?