7-3 Performing Basic Statistical Calculations

Mean, standard deviation, and other statistical values can be obtained from single-variable data and paired- variable data. Regression calculation can also be performed on paired-variable data. All of these calculations are performed using [Calc] menu commands.

Calculating Statistical Values

You can use the procedure below to display a lists of various single-variable and paired-variable statistical values.

uTo display single-variable calculation results

1.On the Stat Editor window or Stat Graph window, tap [Calc] - [One-Variable].

2.On the dialog box that appears, specify the [XList] name, select the [Freq] setting, and then tap [OK].

• This displays the dialog box with the single-variable statistical calculation results described below.

o:

sample mean

Q1:

first quartile

Σx:

sum of data

Med:

median

Σx2:

sum of squares

Q3:

third quartile

σx:

population standard deviation

maxX:

maximum

sx:

sample standard deviation

Mode:

mode*

n:

sample size

ModeN: number of data mode

minX: minimum

 

items

 

 

ModeF: data mode frequency

*If “Mode = 'ModeStat” is displayed, it means that solutions are stored in the “ModeStat” system variable.

To view the “ModeStat” contents, tap any list name cell on the Stat Editor window, input “ModeStat”, and then press E.

Calculation Methods for Q1 and Q3

Q1 and Q3 can be calculated in accordance with the [Q1, Q3 on Data] setting on the Basic Format dialog box (page 34) as described below.

[Q1, Q3 on Data] unchecked (default): With this calculation method, processing depends on whether the number of elements n in the population is an even number or odd number.

 

 

Example: n = 8

 

 

 

 

 

Example: n = 9

 

 

 

 

Lower half group

 

 

Upper half group

 

 

Lower half group

 

Upper half group

 

1

2

3

4

5

6

7

8

1

2

3

4

5

6

7

8

9

 

 

Q1

Median

 

Q3

 

 

 

Q1

 

Median

 

 

Q3

 

 

2 + 3

4 + 5

6 + 7

 

 

2 + 3

 

 

 

7 + 8

 

 

 

2

 

2

 

2

 

 

 

2

 

 

 

 

2

 

￿When n is an even number, using the center point of the total population as the reference, the population elements are divided into two groups: a lower half group and an upper half group. Q1 and Q3 then become the values described below.

Q1 = {median of the group of n/2 items from the bottom of the population} Q3 = {median of the group of n/2 items from the top of the population}

Chapter 7: Statistics Application

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