To determine the correct labels for the given chart, let's carefully analyze the descriptions for each column and match them with the appropriate radio wave terms.
For column [tex]$X$[/tex]:
- "Changes the frequency of a wave"
- "Is used by cell phones to transmit data"
For column [tex]$Y$[/tex]:
- "Changes the height of a wave"
- "Is used by television stations for pictures"
From our knowledge of AM (Amplitude Modulation) and FM (Frequency Modulation):
- AM involves changing the height (amplitude) of the wave, which corresponds to the descriptions for column [tex]$Y$[/tex].
- FM involves changing the frequency of the wave, which corresponds to the descriptions for column [tex]$X$[/tex].
Therefore, the correct headings for the chart should be:
- For [tex]$X$[/tex]: FM (Frequency Modulation)
- For [tex]$Y$[/tex]: AM (Amplitude Modulation)
Thus, the best headings that complete the chart are:
```
X: FM
Y: AM
```