Percentage of 439 Married Graduates of Mount Holyoke College (Women) Graduating 1890 to 1909, who Married at Ages Greater than Any Specific Age Selected from the Horizontal Scale of the Chart

This is a cumulative frequency curve plotted from exactly the same data as Fig. 143. The word "over" with the arrow at the lower left-hand corner of the chart shows that the chart does not indicate the percentage who marry at any age but the number who marry later than any specific age read from the horizontal scale

FREQUENCY CURVES

in Fig. 152 considering the curve "A", 60 per cent of all the telephone calls of this class were answered in "less than" four seconds and 76 per cent of the calls were answered in "less than" five seconds. Of course, all those calls which were observed as having been answered in "less than" four seconds are also answered in "less than" five seconds, so that the curve is on a strictly cumulative basis. In Curve "C" it can be seen that only 30 per cent of the calls of that class were answered in less than four seconds, as against 60 per cent for curve "A". Though curve "A" is higher up on the chart than curve "C", it really represents a smaller length of time required to answer telephone calls than shown by curve "C". Since twice as large a percentage of the calls were answered in "less than" four seconds, .the average time for answering calls in curve "A" is certainly smaller than the average time for curve