Measuring tilt with an MMA7260Q accelerometer

Using Arduino Sensors
2 
Ax = x-Voff/sens;

You are using the read value (x above) as it would be expressed in mV as the other numbers. But this is not the case. analogRead() will return a value from 0 to 1024 proportional to the voltage on the associated pin.

The following holds true:
read value from analogRead() : 1024 = read value in mV : 3.3 V (provided that you connected the AREF to 3.3V)

so if you want x expressed in mV..
x = (analogRead() / 1024) * 3300mV

Hope this helps,

Fabio Varesano