A violin string has a length of 0.350 m and is tuned to concert G, with fG

Question:

A violin string has a length of 0.350 m and is tuned to concert G, with fG = 392 Hz. Where must the violinist place her finger to play concert A, with fA = 440 Hz? If this position is to remain correct to half the width of a finger (that is, to within 0.600 cm), what is the maximum allowable percentage change in the string tension?