MOSCOW, Aug 10. The official exchange rate of the euro against the ruble, set by the Central Bank of the Russian Federation for Wednesday, fell by 8 kopecks — to 86.3578 rubles, the dollar rate increased by 8.84 kopecks — to 73.5962 rubles, follows from the data of the Bank of Russia. Thus, the value of the dual-currency basket (0.55 dollars and 0.45 euros), calculated at official rates, increased by 1.26 kopecks, amounting to 79.3389 rubles.