The frequency of the sound wave doubles when increasing by 1 octave, and halves when decreasing by 1 octave.
The ratio is 2:1. The frequency doubles for each octave that you go up.
It doubles three times. Every time you go up an octave, the frequency doubles.
The frequency of a C of the fourth octave is approximately 261.626 Hz.
That would be 1200 Hz. Every octave is a superposition of the note below it, so the frequency doubles. The octaves above that would be 2400 Hz, 4800 Hz, and so on...
That is 600 Hz as an octave is defined as a doubling of frequency
If you mean "octave", it is a group of eight things. Most commonly it is used to describe the relationship between a musical tone and another which has half or double its frequency. The tone with half the frequency is an octave below and the one with double the frequency is an octave above. It's called an octave because it's the eighth note in a diatonic (major or minor) scale.
150 Hz
The term 'octave' is the name for an interval(space) between two notes. The frequency of the note is doubled, or halved, depending on whether the interval goes up or down in frequency. The two notes are heard toghether as the same, and will also have the same name. For example, an octave above A(440 Hz) is A(880 Hz) an octave under A(440 Hz) is A(220 Hz) To answer the question, the similarity between the keynote and an octave above it, is that the ratio between the frequency of these notes is 1:2 and of course, their names.
1 KHz.
Simply put, an octave per minute doubles the frequency every minute. If you start at 20 Hz at one ocatve per minute you get to 40Hz in one minute, 80Hz in 2 minutes, 160 Hz in three minutes, etc.
That is the frequency of the G Sharp/A flat two octaves below middle C (great octave).