ANSWER:
262 Hz
STEP-BY-STEP EXPLANATION:
We have the following formula to determine the frequency:
[tex]F=440\cdot\mleft(\sqrt[12]{2}\mright)^n[/tex]
According to the statement we can determine that the value of n is equal to -9 (below the concert pitch), therefore we replace and calculate the frequency:
[tex]\begin{gathered} F=440\cdot\mleft(\sqrt[12]{2}\mright)^{-9} \\ F=440\cdot(1.05946)^{-9} \\ F=440\cdot0.5946 \\ F=261.63\cong262\text{ Hz} \end{gathered}[/tex]
Therefore the frequency of middle C is 262 Hz
