Measurements of human skulls from different epochs are analyzed to determine whether they change over time. The maximum breadth is measured for skulls from Egyptian males who lived around 3300 BCE. Results show that those breadths are normally distributed with a mean of 132.6 mm and a standard deviation of 5.4 mm (based on data from Ancient Races of the Thebaid by Thomson and Randall-Maciver).
a. Find the probability of getting a value greater than 140 mm if a skull is randomly selected from the period of around 3300 BCE.
b. Find the value that is D2, the second decile.