99%; n = 12; is unknown; population appears to be normally distributed. Assume that we want

99%; n = 12; σ is unknown; population appears to be normally distributed.

Assume that we want to construct a confidence interval using the given confidence level. Do one of the following, as appropriate: (a) Find the critical value z_α/2, (b) find the critical value t_α/2, (c) state that neither the normal nor the t distribution applies.