Verified answer

Helium follows the ideal gas law very closely, so we can figure the new volume

using the given pressures and absolute (Kelvin) temperatures.

30°C = 303°K and 70°C = 343°K.

Now we can convert the original volume of 3.2 ml by the formula:

3.2 times 343/303 times 207/342.8 = 2.187 ml.

Hope this answers your question!