Thermometer pressure physics problem

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Homework Statement

A constant volume gas thermometer has a pressure of 5830 Pa at 47 °C. What would the pressure be for -99 °C (in Pa)?

Homework Equations

Pf = Pi * (Tf/Ti)

The Attempt at a Solution

Ti = 47 deg C = 320 deg K
Tf = -99 deg C = 174 deg K
Pi = 5830 pa = 0.05755 atm + 1 atm = 15.55 psi
15.55psi * (174/320) = 8.46 psi...Is this how you do it?

 

[BuBbLeS01]

or do i leave it in atm?

 

[BuBbLeS01]

Does anyone know how to do this?