The only detail drawing of a machine part has a dimension smudged beyond legibility. The round in question was created in an automatic screw machine and 1000 parts are in stock. A random sample of 50 parts gave a mean dimension of d? = 0.6241 in and a standard deviation of s = 0.000 581 in. Toleranced dimensions elsewhere are given in integral thousandths of an inch. Estimate the missing information on the drawing.