What is the meaning of: "Your signal report is 5 9 plus 20 dB"?

1. The bandwidth of your signal is 20 decibels above linearity
2. Repeat your transmission on a frequency 20 kHz higher
3. A relative signal-strength meter reading is 20 decibels greater than strength 9 ✓ Correct answer
4. Your signal strength has increased by a factor of 100

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