MATH200B Program — Technical Notes
Copyright © 2007–2022 by Stan Brown, BrownMath.com
Summary:
This document contains the details of variable usage by
the
MATH200B program, and it’s probably of no interest to you unless
you’re programming the TI-83/84 yourself. If you are, you
should also look at
MATH200Z Program — Technical Notes for technical details of the
subprogram that is called by the
MATH200B program.
If you just want to use the statistics utilities in
the MATH200B program, please see MATH200B Program — Extra Statistics Utilities for TI-83/84.
Most parts of the MATH200B program leave useful results in
variables, which you can use for further calculation. Use the
[ALPHA] key. For instance,
if you want a value from variable V, press [ALPHA 6 makes V].
Also, if you’re using any variables or statistics lists
yourself, you don’t want to be surprised when the program changes
their values. Below you’ll find complete information.
If you want to delete the lists to free up memory,
press [2nd + makes MEM] [2] [4], scroll down to find
each one, and press [DEL].
If you want to delete the single-letter variables, though it’s
hardly worth the effort, press [2nd + makes MEM]
[2] [2], cursor to each one, and press [DEL].
Program startup
- G = 1 if running on a high-resolution color screen (TI-84 Plus C
or CE), 0 if running on a low-resolution black-and-white (TI-83+ or
older TI-84), using a technique I learned in the forums at
Cemetech
- J = height of a line in
Text commands: 15 for
high-res, 9 or 7 for low-res
- Q = indention level, 10+15G
1:Skew/kurtosis (calls MATH200Z with
θ = 10)
- E = standard error of skewness, not defined for a probability
distribution
- F = standard error of kurtosis, not defined for a probability
distribution
- K = excess kurtosis (kurtosis minus 3)
- M = mean
- N = sample size (number of data points, or total of frequencies
for a grouped frequency distribution), equals 1 for a probability
distribution
- S = skewness
- W = third moment
- Z = fourth moment
- V = variance (∴ standard deviation is √V
- LD = data list or class midpoints
- LF = class frequencies
- used by program, not useful afterward: GDB0 (deleted), θ
For a probabiliy distribution (N=1), V, S, and K will be the
population values. If N≠1, V, S, and K will be the “as
sample” values.
2:Time series
- N = number of data points
- LD = the numbers from 1 to N
- LF = data list
- used by program, not useful afterward: X
3:Critical t
- A = area of right-hand tail
- D = degrees of freedom
- T = critical t value
4:Critical χ˛
- A = area of right-hand tail
- D = degrees of freedom
- X = critical χ˛ value
5:Infer about σ (calls MATH200Z with
θ = 100)
- C = confidence level (adjusted to >0, <1 if necessary)
- D = degrees of freedom = N−1
- H = high end of confidence interval for σ or
σ˛
- L = low end of confidence interval for σ or
σ˛
- N = sample size
- P = p-value, unrounded
- S = standard deviation of sample
- Z = σ0 from H0
- used by program, not useful afterward: Str0 (deleted), X, θ
6:Correlatn inf (calls MATH200Z with
θ = 200 and 100)
- C = confidence level, or 0 for hypothesis test
- H = high end of confidence interval for ρ
- L = low end of confidence interval for ρ
- N = sample size
- P = p-value for hypothesis test, unrounded
- R = sample correlation coefficient
- T = test statistic for hypothesis test, unrounded
- Z = Fisher Z for confidence interval
- used by program, not useful afterward: LX (deleted), LY
(deleted), θ
7:Regression inf (calls MATH200Z with
θ = 200 and 100)
- A = slope of sample regression line
- B = y intercept of sample regression line
- C = confidence level (adjusted to >0, <1 if necessary)
- M = x̅
- N = sample size
- X = x value entered by user
- Y = ŷ value for X
- LX = x list (deleted)
- LY = y list (deleted)
- used by program, not useful afterward: E, F, S, T, Z, GDB0 (deleted), θ