Interpolation. -- Process of locating data between two known points.

Key. -- See legend.

Lag. -- The condition that exists when two curves are not concurrent, but one "lags" behind the other to some extent.

Legend. -- An explanation or identification of symbols, etc., used in a chart.

Logarithmic Chart. -- See ratio chart.

Logarithmic Scale -- A scale of numbers on a grid so arranged that the spacial intervals are proportional to the differences between the logarithms of the numbers.

Lorenz Chart. -- A chart giving frequency distribution with both the variable and invariable quantities reduced to percentages. Both scales represent 100%. See frequency chart.

Map Chart. -- See statistical map.

Moving Average Curve. -- A curve in which each value is the average for an overlapping period of time. A moving average for a period of time "centered" is the average for half the time before the specified date and half the time after the specified date.

Moving Total Curve. -- A curve in which each value is the total for an overlapping period of time.

Ogive Chart. -- A frequency distribution in which "more than" or "less than" data are presented. One scale of the grid represents percentages and the other scale represents "more than" or "less than" values. See frequency chart.

10(P/o Band Chart. -- See percentage curve chart.

^^"^ GRAPHIC PRESENTATION

100% Bar Chart. -- A chart in which a single bar represents 100% and the divisions of the bar represent percentages of the whole.