The table doesn't seem to be quite accurate, as the actual game accumulates floating point rounding errors. If you dive into the program memory, there's GameHistoryData's miningCostRate and miningSpeedScale variables, which are single precision floats.
| Level Researched | miningCostRate | miningSpeedScale |
|---|---|---|
| None researched | 1.0 | 1.0 |
| 1 | 0.93999999761581 | 1.1000000238419 |
| 2 | 0.88359999656677 | 1.2000000476837 |
| 5 | 0.73390400409698 | 1.5000001192093 |
| 6 | 0.68986976146698 | 1.6000001430511 |