CoinDesk Bitcoin Price Index

Info on how this value was calculated
Based on the following values:
USD:
BTC-e$487.00
Bitstamp$501.78
Bitfinex$503.50
CNY:
BTC China¥3,128.60
OKCoin¥3,134.12
Last updated: Apr 20, 2014 at 19:39 BST

Who is Satoshi Nakamoto?