Can I please get some help with this

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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.

Which of the following is the best first step in solving the equation below? 4+2㏒³x=17