HP 17bII manual Curve Fitting and Forecasting, Logarithmic Curve Fit

Curve Fitting and Forecasting

Curve fitting is a statistical method for finding a relationship between two variables, x and y. Based on this relationship, you can estimate new values of y based on a given x-value, and vice-versa. Each SUM list holds the numbers (data values) for one variable. You can select one of four curve-fitting models:*

y

Linear Curve Fit Exponential Curve Fit

y

Mx

x

x

y

Logarithmic Curve Fit Power Curve Fit

y

M

x

x

*The exponential, logarithmic, and power models are calculated using transformations that allow the data to be fitted by standard linear regression. The equations for these transformations appear in appendix B. The logarithmic model requires positive x-values; the exponential model requires positive y-values; and the power curve requires positive x- and y-values.

10: Running Total and Statistics 133

File name : 17BII-Plus-Manual-E-PRINT-030709 Print data : 2003/7/11