Do one of the following, as appropriate: (a) Find the critical value $\mathrm { z } _ { \alpha / 2 } \text {, (b) find the critical value } \mathrm { t } _ { \alpha / 2 },$ (c) state that neither the normal nor the t distribution applies.
-$99 \% ; n = 17 ; \sigma$ is unknown; population appears to be normally distributed.
A) $\mathrm { z } _ { \alpha / 2 } = 2.583$
B) $\mathrm { z } _ { \alpha / 2 } = 2.567$
C) $\mathrm { t } _ { \alpha / 2 } = 2.898$
D) $\mathrm { t } _ { \alpha / 2 } = 2.921$

Question

Quizplus · Accepted Answer

Since the population standard deviation $\sigma$ is unknown and the sample size is small ($n = 17$), the t-distribution should be used. For a 99% confidence level with 16 degrees of freedom ($n-1$), the critical value is approximately 2.921.

Do One of the Following, as Appropriate: (A) Find the Critical