set y2tics
set ytics nomirror

set angles degree

tstart=9.2
tstop=12.8

g(x)=b

fit g(x) data using ($1>tstart && $1<tstop?$1:1/0):(atan(($3-0.007)/($2+0.073))) via b


plot data_other using 1:2 axes x1y2 with dots title 'other data', \
     data u 1:(atan(($3-0.007)/($2+0.073))) w d t 'data', g(x)