2. Problem
In a normal
distribution 10% of
the items are over
125 and 35% are
under 60. Find the
mean and Standard
Deviation of the
distribution.
35% 10%
X=60
Z=-z₁
μ
Z₂
X=12
5
0
3. Given Information
Let X~N(μ, σ²), where μ, σ² are unknown and are
to be obtained.
Here we are given
P(X>125) =0.1 and P(X<60) =0.35
We know that if X~N(μ, σ²), then the S.N.V is
given by
Z = X – μ
σ