Variable Key Display Variable Type

• When you enter data for one-variable statistics, Xnn represents the

value and Ynn specifies the number of occurrences (frequency).

• When you enter a value for Xnn, the value for Ynn defaults to 1.

Analyzing One-Variable Statistics

To analyze one-variable statistics, select 1-V. Only values for n, v, Sx, sX,

GX, and GX2 are computed and displayed for one-variable statistics.

Analyzing Two-Variable Statistics

You can choose from among these four regression-analysis methods:

• LIN

• Ln

• EXP

• PWR

Computing Values Automatically

Except for the predicted X' and Y' values, the calculator computes and

displays values for statistics variables automatically when you access

them.

Using X' and Y' for Regression Predictions

To use the X' and Y' variables for regression predictions, you either can

enter a value for X' to compute Y' or enter a value for Y' to compute X'.

Regression Models

For two-variable data, the Statistics worksheet uses four regression

models for curve fitting and forecasting.

The calculator interprets the X value as the independent variable and the

Y value as the dependent variable.

The calculator computes the statistical results using these transformed

values:

• LIN uses X and Y.

Model Formula Restrictions

LIN Y = a + b X None

Ln Y = a + b ln(X) All X values > zero

EXP Y = a bx All Y values > zero

PWR Y = a Xb All X and Y values > zero

• Ln uses ln(X) and Y.

• EXP uses X and ln(Y).

• PWR uses ln(X) and ln(Y).

The calculator determines the values for a and b that create the line or

curve that best fits the data.

Correlation Coefficient

The calculator also determines r, the correlation coefficient, which

measures the goodness of fit of the equation with the data. Generally:

• The closer r is to 1 or -1, the better the fit.

• The closer r is to zero, the worse the fit.

Entering Statistical Data

Because the Statistics worksheet lets you enter and display up to 50 data

points, and then stores the values until you clear the worksheet or

change the values, you probably will not have to perform every step for

each Statistics calculation.

1. To select the data-entry portion of the Statistics worksheet, press &

j. X01 is displayed along with any previous value.

2. To clear the worksheet, press & z.

3. Key in a value for X01 and press !.

• For one-variable data, X01 is the first data point.

• For two-variable data, X01 is the first X value.

4. To display the Y01 variable, press #.

5. Key in a value for Y01 and press !.

• For one-variable data, you can enter the number of times the X

value occurs (frequency).

The default value is 1.

• For two-variable data, enter the first Y value.

6. To display the next X variable, press #.

7. Repeat steps 3 through 5 until you enter all of the data points.

Note: To easily scroll up or down through a range of variables, press and

hold # or ".

• When you enter data for one-variable statistics, Xnn represents the

value and Ynn specifies the number of occurrences (frequency).

• When you enter a value for Xnn, the value for Ynn defaults to 1.

Analyzing One-Variable Statistics

To analyze one-variable statistics, select 1-V. Only values for n, v, Sx, sX,

GX, and GX2 are computed and displayed for one-variable statistics.

Analyzing Two-Variable Statistics

You can choose from among these four regression-analysis methods:

• LIN

• Ln

• EXP

• PWR

Computing Values Automatically

Except for the predicted X' and Y' values, the calculator computes and

displays values for statistics variables automatically when you access

them.

Using X' and Y' for Regression Predictions

To use the X' and Y' variables for regression predictions, you either can

enter a value for X' to compute Y' or enter a value for Y' to compute X'.

Regression Models

For two-variable data, the Statistics worksheet uses four regression

models for curve fitting and forecasting.

The calculator interprets the X value as the independent variable and the

Y value as the dependent variable.

The calculator computes the statistical results using these transformed

values:

• LIN uses X and Y.

Model Formula Restrictions

LIN Y = a + b X None

Ln Y = a + b ln(X) All X values > zero

EXP Y = a bx All Y values > zero

PWR Y = a Xb All X and Y values > zero

• Ln uses ln(X) and Y.

• EXP uses X and ln(Y).

• PWR uses ln(X) and ln(Y).

The calculator determines the values for a and b that create the line or

curve that best fits the data.

Correlation Coefficient

The calculator also determines r, the correlation coefficient, which

measures the goodness of fit of the equation with the data. Generally:

• The closer r is to 1 or -1, the better the fit.

• The closer r is to zero, the worse the fit.

Entering Statistical Data

Because the Statistics worksheet lets you enter and display up to 50 data

points, and then stores the values until you clear the worksheet or

change the values, you probably will not have to perform every step for

each Statistics calculation.

1. To select the data-entry portion of the Statistics worksheet, press &

j. X01 is displayed along with any previous value.

2. To clear the worksheet, press & z.

3. Key in a value for X01 and press !.

• For one-variable data, X01 is the first data point.

• For two-variable data, X01 is the first X value.

4. To display the Y01 variable, press #.

5. Key in a value for Y01 and press !.

• For one-variable data, you can enter the number of times the X

value occurs (frequency).

The default value is 1.

• For two-variable data, enter the first Y value.

6. To display the next X variable, press #.

7. Repeat steps 3 through 5 until you enter all of the data points.

Note: To easily scroll up or down through a range of variables, press and

hold # or ".