# [05AB1E](http://github.com/Adriandmen/05AB1E), <s>11</s> 7 bytes

05AB1E uses [CP-1252](http://www.cp1252.com) encoding.

 O¹·-¹/P

[Try it online!](http://05ab1e.tryitonline.net/#code=T8K5wrctwrkvUA&input=WzQyLDQyLDMuMTRd)

**Explanation**

 O # sum input
 ¹ # push input again
 · # multiply by 2
 - # subtract from sum
 ¹/ # divide by input
 P # product