Armstrong Faber produces a standard number-two pencil called Ultra-Lite. Since Chuck Armstrong started Armstrong Faber, sales have grown steadily. With the increase in the price of wood products, however, Chuck has been force to increase the price of the Ultra-Lite pencils. As a result, the demand for Ultra-Lite pencils has been fairly stable over the past 6 years. On the average, Armstrong Faber has sold 457,000 pencils each year. Furthermore, 90% of the time sales have been between 454,000 and 460,000 pencils. It is expected that the sales fallow a normal distributionwith a meanof 457,000 pencils. Estimated the standard deviationof this distribution. (Hint: Work backward from the normal table to find z. Then apply equation.)
This solution provides assistance with determining the standard deviation of the given distribution.