Do one of the following, as appropriate: (a) Find the critical value$ z_{?/2}$, (b) find the critical value $ t_{?/2}$, (c) state that neither the normal nor the t distribution applies
-$91 \% ; \mathrm { n } = 45 ; \sigma$ is known; population appears to be very skewed.
A) $z _ { \alpha / 2 } = 1.70$
B) $\mathrm { z } _ { \alpha / 2 } = 1.75$
C) $\mathrm { t } _ { \alpha / 2 } = 1.645$
D) $\mathrm { t } _ { \alpha / 2 } = 1.34$

Question

Quizplus · Accepted Answer

Since $\sigma$ is known and the sample size is large ($n = 45$), the normal distribution applies despite the population skewness. The critical value $z_{\alpha/2}$ for a 91% confidence level (which leaves 9% in the tails, or 4.5% in each tail) is closest to 1.70, matching option A.

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