- CFA Exams
- 2021 CFA Level I Exam
- Study Session 3. Quantitative Methods (2)
- Reading 11. Hypothesis Testing
- Subject 2. Null Hypothesis and Alternative Hypothesis

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**CFA Practice Question**

The times for untrained rats to run a standard maze has an N(65, 15) distribution where the times are measured in seconds. The researchers hope to show that training improves the times, and they will do so by testing statistical hypotheses. The appropriate alternative hypothesis is ______.

B. H

C. H

A. H

_{a}:μ > 65B. H

_{a}:x-bar > 65C. H

_{a}:μ < 65Correct Answer: C

The alternative hypothesis corresponds to what the researchers are trying to show. If training improves the times, the mice should run the maze in less time, so that the mean will decrease.

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**User Contributed Comments**
9

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

danlan |
Alternative hypothesis is what's needed to show and null hypothesis is what's needed to be rejected. |

johnowens |
We want to show that training improves times. Ha: the times are faster |

gill15 |
Stupid. I was thinking cardio --- and longer they run was what they were testing....just stupid |

sgossett86 |
we have different ways of looking at this. what i see is that someone indicated the null will always be greater or less than or equal to some value. here we see that the docs are trying to prove time is improved. therefore it will be <65 they want to prove. However because the null carries the equal sign, the alternative will be the <65. |

Shaan23 |
Gill...rats working on cardio...thats fantastic |

schweitzdm |
what does N(65,15) mean? |

Rachelle3 |
THE OTHER TWO ANSWERS GO OVER 65 > 65 = MORE THAN 65 FROM THERE YOU KNOW WHAT TO CHOOSE! |

ashish100 |
^ why are you yelling? but thanks. |

shalie |
This hipothesis is one tailed. H0< 65. |