Torricelli Barometer and atmospheric pressure

[bznm]

Homework Statement

I have a Torricelli barometer column filled with mercury.
Situation 1: Temperature1 = 20° C. Height: 0,760 m. Outer pressure:1 atm.
Situation 2: Temperature2 = 35° C. Height: 0,762 m.
Coefficient of termic dilation in the interval (T1, T2): $18,2<br /> *10^-5 (°C)^-1$

Find outer pressure in Situation 2.

2. The attempt at a solution
I used a proportion: $1 atm : 0,760 m = x atm : 0,762 m$. But my result is wrong.
What would you do?
Thank you so much

 

[tiny-tim]

hi bznm!

how did you take account of the thermal expansion in your calculations?