If China's economy grows 4-5% a year, and RMB/CNY appreciates 3-4% a year, then China's effective economic growth rate is 7-9% a year. From Bloomberg:
But China's economy is currently not growing at 4-5% a year in nominal terms. That's the real number not nominal number. You are trying to compute the nominal GDP at current prices in USD, so should use nominal GDP at current prices in yuan along with the currency movement.