Normal Distribution Table

I'm given that:

   Z ~ N(0,1)
   phi(z0) = 0.01
   phi(z1) = 0.025

How do I find z0 and z1, when the smallest value for phi(z) on my Normal Distribution Lookup Table is 0.5000 ?

I recall that my teacher explained a method of doing this a few months back, but cannot seem to remember it..

My guess is something like linking the small value to a larger one which is on the table, and then reversing it later on, perhaps something like this?..

   Z ~ N(0,1)
   phi(z) = 0.01
   phi(z) = 1 - 0.99
   1 - phi(z) = 0.99
   Now what?


Thanks !
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d-glitchConnect With a Mentor Commented:
Does N(0,1) mean a normal distrubution with mean=0 and SD=1??
Is phi the normal curve or the integral of the normal curve?

The normal curve is symmetric around its mean.

If phi(0) = 1.0    then it's the normal curve   and phi(z) = phi(-z)

If phi(0) = 0.5   then it's the integral of the normal curve and  phi(-z) = 1 - phi(z)
InteractiveMindAuthor Commented:
Yer, mean=0, SD=1, phi(0)=0.5, so z in my above example would be about -2.33.


Thank you.
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