1. The problem asks us to calculate the mean (average) volume of gas released from the given data. 2. The volumes given are: $32, 35, 28, 30, 30$ cm$^3$. 3. To find the mean, sum all the volumes and divide by the number of experiments. 4. Calculate the sum: $$32 + 35 + 28 + 30 + 30 = 155$$ 5. There are 5 experiments, so divide the total by 5: $$\frac{155}{5} = 31$$ 6. Therefore, the mean volume of gas released is **31 cm$^3$**.