alleryStart learning →In the notation used for a discrete random variable, what does a lower case letter such as x represent?
AOne specific numerical value the variable takes
BThe random variable's name, spoken in words
CThe probability attached to an outcome
DThe total count of trials performed
Answer & Solution
Correct answer: A. One specific numerical value the variable takes
1. Convention reserves upper case X for the random variable itself, written and read in words.
2. Lower case x is used for one particular numerical value that X can take on.
3. Option B describes upper case X, not lower case x, so it is the wrong role.
4. Options C and D describe a probability and a trial count, neither of which is what x denotes.
_Source: OpenStax Introductory Statistics (CC BY 4.0), Ch 4 "Discrete Random Variables", section 4.1 Probability Distribution Function (PDF) for a Discrete Random Variable_
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