Concept:
First find the area of the shaded region under the standard normal curve and after it as you know total area=1 , so 1-area of shaded region= area of unshaded region.
Answer:
Area of shaded region= P(-2 z
1)
Now,
the symbol Ф represent the cumulative density.
first find the
Ф(1) from the above given table it is equal to 0.8413.
Now,
find the Ф(-2) .
in our table we are given the value of Ф(2)=0.9772.
so as the curve is symmetrical Ф(-2)=1-0.9772=0.0228.
P(-2 z
1)
= Ф(1)-Ф(-2)
= 0.8413-0.0228
= 0.8185
Now,
Area of unshaded region= 1-area of shaded region
= 1- P(-2 z
1)
= 1- 0.8185
= 0.1815
= 0.18
C is the correct answer.