To construct a confidence interval using the given confidence level, do whichever of the following is appropriate. (a) find the critical value z subscript alpha divided by zα/2, (b) find the critical value t subscript alpha divided by tα/2, or (c) state that neither the normal nor the t distribution applies.?

95 % ; n=100; σ = unknown; population appears to be skewed

choose the correct answer below.

a. tα/2 =2.626

b. zα/2 = 1.96

c. tα/2 =1.984

d. zα/2 = 2.575

e. neither the normal nor the t distribution applies

to construct a confidence interval using the given confidence level, do whichever of the following is appropriate. (a) find the critical value z subscript alpha divided by zα/2, (b) find the critical value t subscript alpha divided by tα/2, or (c) state that neither the normal nor the t distribution applies.?

98 % ; n= 19; σ = 21.4; population appears to be normally distributed

a. zα/2 = 2.33

b. tα/2 = 2.214

c. zα/2 = 2.552

d. zα/2 = 2.055

e. neither normal nor t distribution applies