Question

Using the TI 84 calculator, find the area under the standard normal curve. Round the answers to four decimal places.

a) find the area under the standard normal curve to the left of z= -2.16

b) find the area under the standard normal curve to the right of z =-0.04

c) find the area under the standard normal curve that lies between z =-2.3 and z=1.08

d) find the area under the standard normal curve that lies outside the interval between z=-2.45 and z=-0.34

Answer 1

Solution:

A standard normal variable has mean = 0 and SD = 1

Use TI 84 calculator.

Press 2nd and then press VARS

Go to normalcdf(

a)

Area to the left of z= -2.16 is given by

= normalcdf(-100 , -2.16 , 0 , 1)

= 0.0154

b)

Area to the right of z =-0.04 is

= normalcdf(0.04 , 100 , 0 , 1)

= 0.4840

c)

Area between z =-2.3 and z=1.08

= normalcdf(-2.3, 1.08 , 0 , 1)

= 0.8492

d)

Area outside the interval z= -2.45 and z= -0.34

= 1 - Area between z= -2.45 and z= -0.34

= 1 -  normalcdf(-2.45, -0.34 , 0 , 1)

= 0.6402