Test of significance: z-test

• Test is given by = standard normal deviate
  (SND or z)


• SND expresses the difference in standard error
  units on a standard normal curve with = 0 and =1


• For our example, SND = = 2.78

SEX

X 

1. 8 / 100

3. 5  3. 0

-1.96 =3.0^

n

 +1.96

n



0.475 0.475 SND=2.78