1) The lengths of pregnancies are normally distributed with a mean of 266 days and a standard deviation of 15 days.

       a) Find the probability of a pregnancy lasting 307 days or longer.

       b) If the length of pregnancy is in the lowest 2​%, then the baby is premature. Find the length that separates premature babies       from those who are not premature.

2) 

Assume that the Richter scale magnitudes of earthquakes are normally distributed with a mean of 1.087 and a standard deviation of 0.562.

1. Earthquakes with magnitudes less than 2.000 are considered​ “microearthquakes” that are not felt. What percentage of earthquakes fall into this​ category?
2. Earthquakes above 4.0 will cause indoor items to shake. What percentage of earthquakes fall into this​ category?
3. Find the 95th percentile.
4. Will all earthquakes above the 95th percentile cause indoor items to​ shake