Problem 182E

Decide whether a discrete or continuous random variable is the best model for each of the following variables:

(a) The time until a projectile returns to earth.

(b) The number of times a transistor in a computer memory changes state in one operation.

(c) The volume of gasoline that is lost to evaporation during the filling of a gas tank.

(d) The outside diameter of a machined shaft.

Solution:

Step 1 of 5:

In this problem we have to decide the given variables are continuous or discrete random variables.

Discrete random variable: a discrete random variable is a variable, which can only take a countable number of values.

continuous random variable: a continuous random variable is a variable whose value is obtained by measuring.