8) Empirical Rule: The distribution of the length of bolts has a bell shape with a mean of 4 inches and a standard deviation of 0.007 inch. Use the Empirical rule to answer the following questions. a. About 68% of bolts manufactured will be between what lengths? Round to 3 decimals. b. What percentage of bolts will be between 3.986 inches and 4.014 inches? c. If the company discards any bolts less than 3.986 inches or greater than 4.014 inches, what percentage of bolts manufactured will be discarded? d. What percentage of bolts manufactured will be between 4.007 and 4.021 inches