I have three more to go please help

Officer brimberry wrote 24 tickets for traffic violations last week, but only 9 tickets this week. what is the percent decrease? give your answer to the nearest tenth of a percent.

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.

Bring the fraction a/a-4 to a denominator of 16-a^2