Do one of the following, as appropriate:
(a) Find the critical value $z _ { \alpha / 2 }$
(b) find the critical value $t _ { \alpha / 2 }$
(c) state that neither the normal nor the t distribution applies.
90% confidence interval for $\mu$ n=9 ; $\sigma = 4.2$ population appears to be very skewed.
A) $z _ { \alpha / 2 } = 2.896$
B) $z _ { \alpha / 2 } = 2.365$
C) $z _ { \alpha / 2 } = 2.306$
D) Neither the normal nor the t distribution applies.

Question

Do one of the following, as appropriate: 
(a) Find the critical value $z _ { \alpha / 2 }$
(b) find the critical value $t _ { \alpha / 2 }$
(c) state that neither the normal nor the t distribution applies.
90% confidence interval for $\mu$ n=9 ; $\sigma = 4.2$ population appears to be very skewed.
A) $z _ { \alpha / 2 } = 2.896$
B) $z _ { \alpha / 2 } = 2.365$
C) $z _ { \alpha / 2 } = 2.306$
D) Neither the normal nor the t distribution applies.

Quizplus · Accepted Answer

Given the small sample size (n=9) and the population being very skewed, neither the normal (z) nor the t distribution would be appropriate without assuming the population distribution is approximately normal, which is contradicted by the statement of skewness.

Do One of the Following, as Appropriate: (A) Find zα/2z _ { \alpha / 2 }zα/2​

Do One of the Following, as Appropriate:
(A) Find $z _ { \alpha / 2 }$