- CFA Exams
- 2021 CFA Level I Exam
- Study Session 2. Quantitative Methods (1)
- Reading 8. Probability Concepts
- Subject 4. Multiplication Rule for Independent Events

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**CFA Practice Question**

If 15% of the population is left-handed, what is the probability that in a randomly selected group of five people, all five people are left-handed?

B. 0.3333

C. 0.0000759

A. 0.0300

B. 0.3333

C. 0.0000759

Correct Answer: C

p = 0.15

^{5}= 0.0000759###
**User Contributed Comments**
6

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

Iyal |
explaination? |

gambary |
assuming the population size is so large, picking on left handed person will not affect the probabilty of picking another one. thus, each time we picku up a person is an independent event with probability of .15 . so the probability of pikcing 5 left handed ppl out of the population = .15 * .15 * .15 * .15 * .15 = .15^5 |

yanpz |
Suppose "population" is a very large number. Pick one person for 5 times. The 5 events are independent of each other, because the population is large, picking up 1 person won't affect the result of next time picking. For once, P = .15, then for 5 independent events, P = .15*.15*.15*.15*.15 = .0000759 |

Bevin |
Also, intuitively you should know that it will be a very small number. |

magus |
How would you perform this calculation on the BA II Plus? |

johntan1979 |
0.15 y^x 5 = |