Ogive is -

Ans. is 'c' i.e., Cumulative frequency curve Cumulative frequency diagram (OGIVE) o Cumulative relative frequency or cumulative percentage, gives the percentage of persons having a measurement less than or equal to the upper boundary of the class interval. Weight interval (lb) Frequency Relative frequency Cumulative relatives frequency 10-19 5 8.8 8.8 20-29 19 33.3 42.1 30-39 10 17.5 59.6 40-49 13 22.8 82.4 50-59 4 7.0 89.4 60-69 4 7.0 96.4 70-79 2 3.5 99.9 100% Total 57 100 The last column of above table shows the cumulative relative frequency or cumulative percentage. This column is easy to form, you do it by successively accumulating the relative frequencies of each of the various intervals. In the above table the cumulative percentage for the first three intervals is 8.8 + 33.3 + 17.5 = 59.6 and we can say that 59.6% of the children in the data set have a weight of 39.5 lb or less. Or, as another example, 96.4% of children weight 69.5 lb or less. The cumulative relative frequency can be presented graphically. This type of curve is called a cumulative frequency graph or OGIVE. To construct such a graph, we place a point representing the cumulative relative frequency and the points are connected with straight lines. The cumulative frequency graph provides a class of impoant statistics known as percentiles or percentile scores. For example, the 90th percentile is the numerical value that exceeds 90% of the values in the data set and is exceeded by only 10% of them. As another example, the 80th percentile is that numerical value that exceeds 80% of the values contained in the data set and is exceeded by 20% of them, and so on. The 50th percentile is commonly called the median. Uses of Cumulative frequency graph When two cumulative frequency graph, representing two different data sets, are placed on the same graph, they provide a rapid visual comparison without any need to compare individual intervals. Cumulative frequency graph provides an impoant application in the formation of health norms for the monitoring of physical process (weight and height) of infants and children.