Question

(a) Find the area above 27 for a N(15,5) distribution.

Round your answer to three decimal places.

Area =

b) Find the area below 13 for a N(15,5) distribution.

Round your answer to three decimal places.

Area =

Answer 1

Solution :

Given that ,

mean = = 15

standard deviation = = 5

a) P(x > 27) = 1 - p( x< 27)

=1- p P[(x - ) / < (27 - 15) / 5 ]

=1- P(z < 2.4)

Using z table,

= 1 - 0.992

= 0.008

b) P(x < 13) = P[(x - ) / < (13 - 15) / 5]

= P(z < -0.4)

Using z table,

= 0.345