- CFA Exams
- CFA Level I Exam
- Topic 1. Quantitative Methods
- Learning Module 5. Sampling and Estimation
- Subject 5. Confidence Intervals for the Population Mean and Selection of Sample Size

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**CFA Practice Question**

As sample size increases, ______

B. degrees of freedom decrease.

C. confidence interval width increases.

A. critical values for t decrease.

B. degrees of freedom decrease.

C. confidence interval width increases.

Correct Answer: A

As sample size increases, degrees of freedom increase and critical values for t decrease. Thus, the amount added to or subtracted from the sample mean to create the confidence interval will decrease. Therefore, confidence interval width will decrease.

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**User Contributed Comments**
3

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

Yurik74 |
What are critical values? |

benji1983 |
I think the critical values can be found from the t-distribution table. |

EminYus |
process of elimination..you know B is false because as sample size increase, so does DF and you know C is false because is N increase, the width decreases |