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. 91%; n = 45; σ is...

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.


91%; n = 45; σ is known; population appears to be very skewed.