Question 2.Arm and Strong produces a standard number-2 pencil called Super-Lite. Since Arm and Strong started, sales have grown steadily. With the increase in the price of wood products, Arm and Strong has been forced to increase the price of the Super-Lite pencils. As a result, the demand of Super-Lite has be fairly stable over the past 6 years. On the average, Arm and Strong has sold 547,000 pencils each year. Furthermore, 90% of the time sales have been between 454,000 and 460,000 pencils. It is expected that the sales follow a normal distribution.

(Hint: work backward from the normal table to find z. Apply the equation below.)