Logarithmic Regression
The logarithmic regression option finds the equation of
the form y = a + b ln x that best fits a set of data.
First, enter the data.
The values of x must, of course, be greater than zero.
The data shown here are the points {(2,11.4), (3,17), (5,27.3), (7,36.1), (11,47.7), (13,49.9)}.
Press 
to view the statistics calculation options.
Press 
for regressions, then
to select logarithmic.
Therefore, the best-fit logarithmic equation for this data is approximately y = - 5.45 + 21.5 ln x.
The correlation coefficient, r, is about 0.995 and the coefficient of determination, r2, is about 0.991.
which indicates a very good fit.
Note: If an error message occurs, make
sure the data was entered correctly or press
to view the setup.
Use 
, 
,
and the menu keys to select List1 for 2Var XList,
List2 for 2Var YList,
and 1 for 2Var Freq.