Practical uses of knowing variation

Answer one of the following.
· Give some practical uses of knowing variation. A few thoughts: You are traveling to a job interview; what clothes do you need to pack for a trip? Doctors need to know distributions of blood values to know whether a patient is out of range; industrial engineers need to know distributions, for example the strength of a certain part to see if there is a problem with a manufacturing machine; clothing manufacturers need to know the distribution of sizes, for example children’s clothes for a certain age.

· For many years, the New York subway had no air conditioning on the grounds that the average trip was only 15 minutes, and 15 minutes without air conditioning is no hardship, even in the New York summer. Critique this reasoning.