The logarithmic regression option finds the equation of a logarithmic equation of the form y = a + b ln x that best fits a set of data. First, press selecting option AEDIT to enter the data .

The data shown here is the points {(2,11.4) (3,17) (5,27.3) (7,36.1) (11,47.7) (13,49.9)}

Press DREG to view the regression options.

For logarithmic regression, select opton 07Rg_ln for base e using followed by six

or 08Rg_log for base 10 using eight

Press and select cubic regression in the calculation screen. Now press followed by .

Therefore, the best-fit logarithmic equations for this data are

The regression equation can be automatically stored in the equation editor by entering the name of the equation, such as y1, after (L1,L2 as follows: choose option A and select y1 followed by .