<PRE><B>Question 1197039</B>
&lt;br&gt;
The work in the response from the other tutor is very hard to follow, largely because she keeps units in all her calculations and displays them poorly.  In the end a mysterious factor of 8 appears which makes her answer incorrect -- a fact she could easily have seen if she had checked her answer.&lt;br&gt;
In fact all you need to do to solve the problem is use her initial equation and fill in the numbers:&lt;br&gt;
{{{v1*p1=v2*p2}}}
{{{12*13=v2(4)}}}
{{{v2=156/4=39}}}&lt;br&gt;
ANSWER: 39 cubic feet&lt;br&gt;
I personally would not even have used the fact that the product of the volume and pressure is a constant.  The information is not given that way; and solving the problem using the inverse variation fact is far easier.&lt;br&gt;
Between the two scenarios, the pressure changes by a factor of 4/13; the inverse variation says the volume changes by a factor of 13/4:&lt;br&gt;
{{{12*(13/4)=3*13=39}}}&lt;br&gt;
ANSWER: 39&lt;br&gt;
</PRE>