A researcher studies the wages () pattern of 131 workers that work for a firm. He finds that the wages () pattern of the workers is normally distributed with a mean of $47.5 and a standard deviation...

A researcher studies the wages () pattern of 131 workers that work for a firm. He finds that the wages () pattern of the workers is normally distributed with a mean of $47.5 and a standard deviation of $8.78.

(a) The probability that a worker earns at least $50.

(b) The probability that a worker earns between $40 and $60.

(c) Find the wage of a worker whose wage is lower than that of the 20% of all workers’ wage.

(d) Find the wage of a worker whose wage is greater than that of the 90% of all workers’ wage.