Determine the value of Z0 which satisfies Pz Z0 09Solutio

Determine the value of Z0 which satisfies P(z < Z0 ) = 0.9

Solution

Mean ( u ) =0
Standard Deviation ( sd )=1
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
P ( Z < x ) = 0.9
Value of z to the cumulative probability of 0.9 from normal table is 1.282
P( x-u/s.d < x - 0/1 ) = 0.9
That is, ( x - 0/1 ) = 1.28
--> x = 1.28 * 1 + 0 = 1.282