Question

Find the area of the shadedregion The graph to the world, and these scores omaly m o The area of the region und fordem e s as needed

Answer 1

Solution:

We are given

Mean = 100

SD = 15

We have to find P(100<X<120)

P(100<X<120) = P(X<120) – P(X<100)

Z = (X – mean) / SD

For X = 120

Z = (120 – 100)/15

Z = 20/15

Z = 1.333333

P(Z< 1.333333) = P(X<120) = 0.908789

(by using z-table)

For X=100

Z = (100 – 100)/15

Z = 0

P(Z<0) = P(X<100) = 0.5

(by using z-table)

P(100<X<120) = P(X<120) – P(X<100)

P(100<X<120) = 0.908789 – 0.5

P(100<X<120) = 0.408789

Required probability = 0.4088