Need help with this "if, then" statement.

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.

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

Which of the following graphs could represent a quartic function?