The note "Middle C" is known to have a frequency of 261.6 Hz. What would

be the frequency of a note one octave higher?

Answer: frequency = 523.2 Hz

Explanation:

One octave higher = 2f of the last octave.

For instance, if C2 = 4 Hz

A octave higher will be C3 in which its frequency will be 2 * 4Hz = 8Hz

Back to the question.

One octave higher frequency will therefore equal to:

2f = 2 * 261.6 = 523.2 Hz