What is the missing step in this proof?

What is the volume of a rectangular prism if the length is 10.4 mm the width is 5 mm in the height is 8 mm

The lengths of nails produced in a factory are normally distributed with a mean of 4.91 centimeters and a standard deviation of 0.05 centimeters. find the two lengths that separate the top 4% and the bottom 4%. these lengths could serve as limits used to identify which nails should be rejected. round your answer to the nearest hundredth, if necessary.

Divide. reduce the answer to lowest terms.5 2/3 ÷ 3 1/9