Correct option is A
The relationship between the standard error of the mean (SEXˉSE_{\bar{X}}
SEX̄) and the population standard deviation (σ\sigmaσ) is given by:

Information Booster:
The standard error of the mean (SEX̄) is an important concept in inferential statistics. It quantifies the accuracy of the sample mean (X̄) as an estimate of the population mean (μ\muμ). The formula for SEX̄ is:

- σ: Population standard deviation.
- nnn: Sample size.
Key Takeaways:
- As nnn increases, SEX̄SEXˉSE_{\bar{X}}ˉ decreases, making the sample mean a more precise estimate of the population mean.
- SEX̄ is inversely proportional to √n, meaning the error reduces as the sample size grows.
The ratio provided helps determine the sample size needed for a specific level of precision in estimation.