Determine whether the value is a discrete random variable, continuous random variable, or not a random variable.

(a) The number of hits to a website in a day
(b) The amount of rain in City Upper B during April
(c) The response to the survey question "Did you smoke in the last week question mark "
(d) The number of statistics students now reading a book
(e) The number of light bulbs that burn out in the next week in a room with 16 bulbs
(f) The height of a randomly selected giraffe

A discrete random variable is a variable that takes a countable number of values and the sum of all of them equals one; it depends on a random phenomenon.

A continuous random variable is a variable that can take an infinite uncountable values (for example in the real numbers) and it depends on a random phenomenon

With these definitions in mind we have:

a) The number of hits to a website in a day: Discrete random variable (it takes a countable number of values (1,2,3,4...)

b)The amount of rain in City Upper B during April: Continuous random variable (the amount of rain falls in the real numbers)

c) The response to the survey question "Did you smoke in the last week?": not a random variable. There are only two answers: yes or no.

d) The number of statistics students now reading a book: Discrete variable (it can be 1, 2, 3,4,... students)

e) The number of light bulbs that burn out in the next week in a room with 16 bulbs: Discrete random variable (the possible outcomes are 0,1,2...15,16)

f) The height of a randomly selected giraffe: Continuous random variable. (the height values are real numbers)