A student uses a Geiger-Muller tube and counter to measure the radiation emitted by a radioactive source. Constant background radiation has already been subtracted from the results.
The table below shows five consecutive count rate measurements taken over identical 1-minute intervals.
| Measurement | Count rate (counts per minute) |
|---|---|
| 1st | 154 |
| 2nd | 148 |
| 3rd | 159 |
| 4th | 151 |
| 5th | 155 |
State how the data in the table shows that radioactive decay is a random process.