请看这句东方作文教程的话,为什么unfair前没动词

moreover, it is possible that a few relatively high-priced or low-priced properties skewed these averages, rendering any conclusions about the comparative quality of the two firms based on these averages unfair.

如上，rendering这句算什么成分？放在后面和放在前面是一样的么?如果在unfair前加动词，那是不是就不对了？

谢谢!

unfair是修饰rendering any conclusion的吗？

如果单独拿出来作句子rendering any conclusions about the comparative quality of the two firms based on these averages is unfair.这样可以吗？