Calculator Notes for TI-89, TI-92 Plus, and Voyage 200

Note 13D • Creating Random Probability Distributions (continued) TI-89/TI-92 Plus/Voyage 200
d. To create a right-skewed distribution, use the cube of rand(. In this
example, the command seq(2030(rand())^3,x,1,200)→p1 creates a
right-skewed population of 200 values between 20 and 50.
[20, 50, 2, 0, 50, 1]
Note 13E • Sampling from a Distribution
Before starting the sampling routine, make sure that you have stored your
distribution into a list p1 (see Note 13D), calculated the population mean
and standard deviation, and graphed y1, y22x and y32x.
Now, the recursive routine below will randomly choose one value at a time
from list p1 and add it to a sample, and then plot a point in the form
(number sampled, sample mean). In the routine, the variable n is the number
sampled and the variable t is the sum of the data values. Hence, the routine
plots the point (n, tn).
a. Initialize n to 0 by pressing 0 STOÍ alpha [N] ENTER .
b. Initialize t to 0 by pressing 0 STOÍ T ENTER .
c. Enter this recursive routine on the Home screen:
n1→n: tp1[rand(200)]→t: PtOn n, tn
Find the rand( command by pressing 2nd [MATH] 7:Probability 4:rand(. Find
the point plotting command, PtOn, by pressing CATALOG [P] and scrolling
down to PtOn. Get the colon by pressing 2nd [:].
d. Begin the sampling-and-plotting routine by pressing ENTER HOME ENTER
HOME , and so on. Each time you press ENTER , you’ll see a new point
plotted on the graph.
Note 13F • Correlation Coefficient
[0, 50, 10, 20, 20, 1]
There are two ways to find a correlation coefficient, r, using your calculator.
You can manually enter the calculations yourself, or you can have the
calculator do the work for you.
First store your bivariate data into two lists, say list w1 for the x-values and
list w2 for the y-values.
Discovering Advanced Algebra Calculator Notes for the Texas Instruments TI-89, TI-92 Plus, and Voyage 200 CHAPTER 13 79
©2004 Key Curriculum Press
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