Question 41608
Pressure P is directly proportional to temperature T, so let 
{{{P = c*T}}}__________(1) 
where c = arbitrary constant of variation/proportionality.
When T = 280 K, P = 2 psi.
Substitute these values P = 2 and T = 280 in eqn. (1) 
so {{{2 = c*280}}}
or {{{c = 2/280}}} = {{{1/140}}}


Thus substituting this value in eqn. (1) we have
{{{P = (1/140)*T}}}
or T = 140P


This is the appropriate direct variation equation.