Which critical value is appropriate for a 99% confidence level where n=17 ;$\sigma$ is unknown and the population appears to be normally distributed?
A) $t _ { \alpha / 2 } = 2.898$
B) $z _ { \alpha / 2 } = 2.583$
C) $t _ { \alpha / 2 } = 2.921$
D) $z _ { \alpha / 2 } = 2.567$

Question

Which critical value is appropriate for a  99% confidence level where  n=17 ;$\sigma$ is unknown and the population appears to be normally distributed?
A) $t _ { \alpha / 2 } = 2.898$
B) $z _ { \alpha / 2 } = 2.583$
C) $t _ { \alpha / 2 } = 2.921$
D) $z _ { \alpha / 2 } = 2.567$

Quizplus · Accepted Answer

Since the sample size is small (n=17), $\sigma$ is unknown, and the population is normally distributed, the t-distribution should be used. For a 99% confidence level with 16 degrees of freedom (n-1), the critical value is $t _ { \alpha / 2 } = 2.921$.

Which Critical Value Is Appropriate for a 99% Confidence σ\sigmaσ

Which Critical Value Is Appropriate for a 99% Confidence $\sigma$