The three grades collected tree species, the number collected by the sixth grade was 1.5 times that of the fifth grade, and the number collected by the fourth grade was that of the fifth grade (8/9). The fifth grade collected 72 kilograms of tree species. How many kilograms of tree species were collected in the fourth, fifth and sixth grades?
三个年级学生采集树种，六年级采集的是五年级的1.5倍，四年级采集的是五年级的(8/9)．五年级采集了72千克树种．四、五、六年级共采集了多少千克树种？
<result>203</result>