- CFA Exams
- CFA Exam: Level I 2021
- Study Session 3. Quantitative Methods (2)
- Reading 9. Common Probability Distributions
- Subject 2. Probability Function

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**CFA Practice Question**

Which of the following is (are) NOT (a) key property (properties) of a probability function?

II. The sum of all probabilities over the entire range of the random variable must equal 1.

B. II only.

C. None of the above.

I. Each individual probability must lie between 0 and 1 inclusive.

II. The sum of all probabilities over the entire range of the random variable must equal 1.

A. I only.

B. II only.

C. None of the above.

Correct Answer: C

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**User Contributed Comments**
10

User |
Comment |
---|---|

surob |
Why II is incorrect? |

surob |
Never mind. I should have read the question carefully. |

eb2568 |
...it happens to the rest of us |

dnoyelles |
that's really annoying. |

bobert |
NOT NOT NOT NOT.... hate that word |

MattyBo |
1. Can't have probability < 0% 2. Probability must add to 100% |

Shalva |
I love this site |

CFAonTheBrain |
i should read the question more carefully |

AUAU |
TRICKY of "NOT" CFAI exam like this kind of wordings. e.g. least likely, most likely, etc. |

bundy |
Probability P(X=x) is a number btw 0 and 1 The sum of the probabilities P(X=x)over all values of x = 1 |