11–4 Statistical Operations
Statistical Calculations
Once you have entered your data, you can use the functions in the statistics menus.
Statistics Menus
Menu Key Description
L.R.
|
The linear–regression menu: linear
estimation {
º
ˆ
} {
¸
ˆ
} and curve–fitting {
T
} {
P
}
{
E
}. See ''Linear Regression'' later in this
chapter.
,
|
The mean menu: {
º
} {
¸
} {
·º
}. See
"Mean" below.
s,
σ
|
The standard–deviation menu: {
Uº
} {
U¸
}
{
σ
º
} {
σ
¸
}. See "Sample Standard
Deviation" and "Population Standard
Deviation" later in this chapter.
SUMS
|
The summation menu: {
Q
} {
;º
} {
;¸
} {
;º
}
{
;¸
} {
;º¸
}. See "Summation Statistics"
later in this chapter.
Mean
Mean is the arithmetic average of a group of numbers.
Press
|
{
º
} for the mean of the x–values.
Press
|
{
¸
} for the mean of the y–values.
Press
|
{
·º
}for the weighted mean of the x–values using the
y–values as weights or frequencies. The weights can be integers or
non–integers.
Example: Mean (One Variable).
Production supervisor May Kitt wants to determine the average time that a certain
process takes. She randomly picks six people, observes each one as he or she
carries out the process, and records the time required (in minutes):
