in employment discrimination cases, courts have held that there is proof of discrimination when the percentage of blacks among the firm's employees is lower than the percentage of blacks in the surrounding geographical region, provided the difference is statistically significant by the z-test. Suppose that in one city, 10% of the people are black. Suppose too that every firm in the city hires employees by a process which, as far as race is concerned, is equivalent to simple random sampling. Would any of these firms ever be found guilty of discrimination by the z-test? Explain briefly.