Question

Calculate Zα / 2 in the following sections

a) With a confidence level of 96%
b) With a confidence level of 99.5% and 92%
c) with a significance level of 2% and 7%
d) With α = 0.03 and α = 0.11

Answer 1

a)

from excel:

 Zα / 2 =normsinv((1+0.96)/2)=2.05

b)

With a confidence level of 99.5% ;  Zα / 2 =normsinv((1+0.995)/2)=2.81

With a confidence level of 92% ; Zα / 2 =normsinv((1+0.92)/2)=1.75

c)

with a significance level of 2% ;  Zα / 2 =normsinv(1-0.02/2)=2.33

with a significance level of 7% ;  Zα / 2 =normsinv(1-0.07/2)=1.81

d)

with a significance level of 0.03 ;  Zα / 2 =normsinv(1-0.03/2)=2.17

with a significance level of 0.11 ;  Zα / 2 =normsinv(1-0.11/2)=1.60