The probability density function for an exponential random variable x has a graph called a bell ...

The probability density function for an exponential random variable x has a graph called a bell
  curve.
 
  A) True B) False

Q. 2

The exponential distribution is sometimes called the waiting-time distribution, because it is used
  to describe the length of time between occurrences of random events.
 
  A) True B) False

Q. 3

After a particular heavy snowstorm, the depth of snow reported in a mountain village followed
  a uniform distribution over the interval from 15 to 22 inches of snow. Find the standard
  deviation of the snowfall amounts.
 
  A) 18.5 inches B) 2.02 inches C) 4.08 inches D) 1.42 inches

Q. 4

The age of customers at a local hardware store follows a uniform distribution over the interval
  from 18 to 60 years old. Find the average age of customers to this hardware store.
 
  A) 39 years old B) 50 years old C) 45 years old D) 60 years old