If the area probability is given as 098 isnt it not enough d

If the area (probability) is given as 0.98 isnt it not enough digits to know the z?

Cuz there is alot of 0.9803,0.9808?

How do i do this

Find z, such that P(Z z) = 0.98 P(Z z) = 0.02

If the area is given then it is sufficient to find z-value.

This we can done by using EXCEL.

P(Z < z) = 0.98

This is left tailed probability.

EXCEL syntax :

=NORMSINV(probability)

where probability = 0.98

z = 2.05

P(Z > z) = 0.98

EXCEL syntax :

=1-NORMSINV(probability) (EXCEL always gives left tailed probability)

z = -1.05

P(Z < z) = 0.02

z = -2.05

P(Z > z) = 0.02

z = 3.05