Question

Find the area under the standard normal curve and shade it in on the given curve. (4 decimal places) Write the calculator commands used.

A. ?(−1.3 < ? < 1.5)

Answer 1

Using standard normal z-table we find, P(-1.3 < Z < 1.5)

P(-1.3 < Z < 1.5)

= P(Z < 1.5) - P(Z < -1.3)

= P(Z < 1.5) - [ 1 - P(Z < 1.3) ]

= 0.9332 - [ 1 - 0.9032 ]

= 0.9332 - 0.0968

= 0.8364

=> P(-1.3 < Z < 1.5) = 0.8364

Note : Using TI-83 plus calculator, we get the required probability = 0.8364