A researcher investigated the rate of photosynthesis in the freshwater macrophyte Ceratophyllum demersum by measuring the volume of oxygen gas produced in different concentrations of sodium hydrogencarbonate (NaHCO3\text{NaHCO}_3NaHCO3) solution. The results of this investigation are shown in the table below:
| Concentration of NaHCO3\text{NaHCO}_3NaHCO3 (%) | Volume of oxygen collected in 12 minutes (cm3\text{cm}^3cm3) | Rate of oxygen production (cm3/hour\text{cm}^3/\text{hour}cm3/hour) |
|---|---|---|
| 0.1 | 0.24 | 1.20 |
| 0.2 | 0.52 | 2.60 |
| 0.3 | 0.76 | ZZZ |
| 0.4 | 0.92 | 4.60 |
| 0.5 | 0.98 | 4.90 |
Calculate the value of Z Z\,Z in the table.