Solution: In 2006, the grain output in mountainous and hilly areas reached _17.2 million kilograms.

By the end of 2008, the total grain output will reach _ _ 4,888.14,000 kg, and the grain output in mountainous and hilly areas will reach _ _1774.54 _ 10,000 kg.

By the end of 2008, the grain in mountainous and hilly areas will increase by X.

According to the meaning of the question, _ _1720 (1+x)+313.6 = 4888.14 _ _ _ _ _ _ x = 0.000.

A: By the end of 2008, the grain in mountainous and hilly areas should increase by _ _ 3.2 _ _%.