6 To estimate the proportion of unemployed workers in a big city in Turkey, an economist selected at random 400 people. Of these, 25 were unemployed. (a) Identify the research question and the population. (b) Estimate the true proportion of unemployed workers and give the margin of error in the estimation with 99% confidence. (c) How many people must be sampled to reduce the margin of error to at most 0.01? ISKUR is OLMASAN GREMEZ