The statistical method of Briden and Ward is reconsidered to derive an easy but exact method to calculate true mean inclination and precision parameter when the data consist of only inclinations. Expectations of sin I, sin2 I, etc. are obtained for samples of following the Fisher distribution. The best estimate of the mean inclination and precision parameter can easily be calculated as solutions of two nonlinear simultaneous equations. This method applies equally well to whichever of inclinations or virtual geomagnetic latitudes having the Fisher distribution.