# Normal Distribution on the TI89 using Statistics Made Easy

ex1. What is the probability of obtaining a sample mean greater than M=60 for a random sample of n=16 scores selected from a normal population with a mean of 65 and a standard deviation of 20?

Go To F3 7 and select Normal distribution, enter
mu=65
std dev=20/sqrt(16)=20/4 = 5 so just enter 5
M = 60

Then in the dropdown menu select option 2: P(x>a) . Voila 84.1345%

ex2. What are the boundaries for the middle 50% of all possible random samples of n=25 scores selected from a normal population with a mean of 80 and a standard deviation of 10?

Go To F3 7 , enter
mu=80
std dev=10/sqrt(25)=10/5 = 2 so just enter 2
and in the dropdown menu select 6 NormInverse :
enter .25 (for the left 50% bound)
next redo above and enter .75 to the upper right bound.

Also, is there any way to use SPME to obtain or calculate values found in Statistical unit normal tables?

Sure, F3 7 . Use mu=1 and Std Dev=0 and a and b is desired , then use options 1, 2, 3 in the dropdown menu.