+------------+--------+---------+--------+---------+ | DATES | WITH | RIGHT | LEFT | AGAINST | +------------+--------+---------+--------+---------+ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +------------+--------+---------+--------+---------+ | Sums | | | | | +------------+--------+---------+--------+---------+ |Percentages | | | | | +------------+--------+---------+--------+---------+ At the bottom of each column write down the number of cases in that column, and then determine the percentages which these cases are of the total number of observations. This is done by dividing the number of cases in each column by the sum-total of all the observations. When you have obtained the percentage of each kind of wind direction, you have a numerical result. A graphical presentation of the results may be made by laying off radii corresponding in position to those which divide the sectors in Fig. 46, and whose lengths are proportionate to the percentages of the different wind directions in the table. Thus, for a percentage of 20, the radii may be made 1 inch long, for 40%, 2 inches, etc. When completed, the relative sizes of the sectors will show the relative frequencies of winds blowing in the four different directions with reference to the gradient, as is indicated in Fig. 47.