Statistical Variables - Texas Instruments TI-89 Manual Book

Statistical Variables

Calculated Variables
To type the character G ,
press:
¥ c ¤
TI-89: [S]
2 ¤
TI-92 Plus: G S
To type the character s ,
press:
TI-89: ¥ c j [S]
TI-92 Plus: 2 G S
Tip: To type a power (such
as 2 in Gxñ ), ü, or ý ,
press
2 ¿ and select it from
the Math menu.
Note: 1st quartile is the
median of points between
minX and medStat, and 3rd
quartile is the median of points
between medStat and maxX.
Tip: If regeq is 4x + 7, then
regCoef is {4 7}. To access
the "a" coefficient (the 1st
element in the list), use an
index such as regCoef[1].
Statistical calculation results are stored to variables. To access
these variables, type the variable name or use the
screen as described in Chapter 21. All statistical variables are
cleared when you edit the data or change the calculation type.
Other conditions that clear the variables are listed on
page 260.
Statistical variables are stored as system variables. However,
and are treated as a list and a function variable, respectively.
regeq
mean of x values
sum of x values
sum of values
xñ
sample std. deviation of
population std. deviation of
number of data points
mean of values
y
sum of values
y
sum of values
yñ
sample standard deviation of
population std. deviation of
sum of values
xù y
minimum of x values
maximum of values
x
minimum of y values
maximum of values
y
1st quartile
median
3rd quartile
regression equation
regression coefficients (
correlation coefficient ††
coefficient of determination ††
summary points
(MedMed only) †
† The indicated variables are calculated but are not shown on the
screen.
STAT VARS
†† corr is defined for a linear regression only;
polynomial regressions.
One
Var
ü
Gx
Gxñ
x Sx
† sx
x
nStat
y
†
y
minX
maxX
q1
medStat
q3
, , , , )
a b c d e
Chapter 16: Statistics and Data Plots
VAR-LINK
regCoef
Two
Var Regressions
ü
Gx
Gxñ
Sx
sx
nStat
ÿ
Gy
Gyñ
Sy
sy
Gxy
minX
maxX
minY
maxY
regeq
regCoef
corr
Rñ
medx1, medy1,
medx2, medy2,
medx3, medy3
Rñ is defined for all
263