What's a best simple definition for a outlier in math

The weights of broilers (commercially raised chickens) are approximately normally distributed with mean 1387 grams and standard deviation 161 grams. what is the probability that a randomly selected broiler weighs more than 1,425 grams?

Askate shop rents roller skates as shown on the table below. which graph and function models this situation?

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.