Logarithmic Regression
The logarithmic regression option finds the equation of
the form y = a + b ln x that best fits a set of data.
Press 
to
choose the statistics application. Choose fit data... and press
.
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 choose a statistics calculation option.
Select Logarithmic Fit and press .
Press 
to calculate the regression.
The regression equation is in level 3 of the stack, the correlation in level 2, and
covariance in level 1. To view the entire correlation press
. Press
again to see the regression equation itself.
Therefore, the best-fit logarithmic equation for this data is approximately
y = -5.45 + 21.54 ln x.