The speed of sound in room temperature (left(20^{circ} mathrm{C} ight)) air is (343 mathrm{~m} / mathrm{s}); in

The speed of sound in room temperature \(\left(20^{\circ} \mathrm{C}\right)\) air is \(343 \mathrm{~m} / \mathrm{s}\); in room temperature helium, it is \(1010 \mathrm{~m} / \mathrm{s}\). The fundamental frequency of an open-closed tube is \(315 \mathrm{~Hz}\) when the tube is filled with air. What is the fundamental frequency if the air is replaced with helium?