The following observations relate to the height of a group of persons. Draw the two types of cumulative frequency polygons and cumulative frequency curves and determine the median. Height in cms                                                    Frequency 140-143 143-146 146-149 149-152 152-155 155-158 158-161 161-164 164-167 167-170 170-173 173-176 176-179 179-182     3 9 26 31 45 64 78 85 96 72 60 43 20 6

The following table shows the distribution of the heights of a group of factory workers : Draw the 'less than' cumulative frequency curve on graph paper . Use 2 cm = 5 cm height on one axis and 2 cm = 10 workers on the other {:(" Ht. (cm): ", 150- 155, 155-160, 160-165, 165-170, 170-175, 175-180, 180-185),(" No. of workers " ," "6, " "12, " "18, " "20, " "13, " "8, " "6):}

The heights of 50 students, measured to the nearest centimetres, have been found to be as follows: 161 150 154 165 168 161 154 162 150 151162 164 171 165 158 154 156 172 160 170153 159 161 170 162 165 166 168 165 164154 152 153 156 158 162 160 161 173 166161 159 162 167 168 159 158 153 154 159 (i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160 - 165, 165 - 170, etc.(ii) What can you conclude about their heights from the table?

The heights (in cm) of 30 students of class VIII are given below: 155,158,154,158,160,148,149,150,153,159,161,148,157, 153,157,162,159,151,154,156,152,156,160,152,147,155,163,155, 157,153 Prepare a frequency distribution table with 160-164 as one of the class intervals.

The heights, to the nearest cm, of 30 men are given below: {:(159, 170, 174, 173, 175, 160, 161, 164, 163, 165), (164, 171, 162, 170, 177, 185, 181, 180, 175, 165), (186, 174, 168, 168, 176, 176, 165, 175, 167, 180):} Using class intervals 155 - 160, 160 - 165, ... draw up a grouped frequency distribution and use this to estimate the Arithmetic mean and standard deviation.