A student investigates the relationship between the pressure and volume of a fixed mass of gas in a closed container at a constant temperature. The student plots a graph of the results:

Show, using two sets of values from the graph, that the pressure of the gas is inversely proportional to its volume (P∝1VP \propto \frac{1}{V}P∝V1).
Complete the following sentences about how volume and pressure are related at a constant temperature. Choose your answers from the words below. Each word can be used once, more than once, or not at all:
doubled** | halved | **the same
In another experiment, the student measures how the pressure of a gas changes as its temperature in degrees Celsius (∘C^{\circ}\text{C}∘C) increases. The volume of the container is kept constant. The results are plotted below:

Explain how the pressure is related to the temperature in degrees Celsius (∘C^{\circ}\text{C}∘C). Use features of the graph to support your answer.