A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperature of \(27^\circ C\) two successive resonances are produced at \(20\,cm\) and \(73\,cm\) of column length. If the frequency of the tuning fork is \(320\,Hz\), the velocity of sound in air at \(27^\circ C\) is