The formatting made it hard to tell what you were trying to say in your email, but when calculating the effect of temperature on pressure you can use Charles Law:
You gave these values:
Plugging in the values:
Multiplying both sides of the equation by P
_{2} and switching sides around the equals sign:
Now we can multiply both sides by 499.2:
And now we can divide both sides by 546:
And doing the math gives us:
Which is roughly the same answer you got, except that you were a little off because you rounded 39.2 into 39, so it looks like your method was correct.