Do one of the following, as appropriate . (a) Find the critica value z a/2; (b) find the critica value t a/2; (c) state that neither the normal nor the t distribution applies. Confidence level 99%; n=22; sigma is unknown; population appears to be normally distributed.
a. t a/2 = 2.518
b. t a/2 = 2.831
c. z a/2 = 2.33
d. z a/2 = 2.575
e. Neither normal nor t distribution applies.
I need to know how to get the answers..