If two quentities (V, P) are very inversely, so

Where k is the constant of variation, we can get it by using the initial values of V and P
Let us use the second rule
Since V is 248 cubic inches when P is 5 pounds per square inch, then

We need to find V when P = 7 pounds per square inch

Let us substitute these values in the second rule

By using cross multiplication

Divide both sides by 7

Round it to the nearest integer

The volume of the gas is 177 cubic inches