The process reaction curve for a unit step input is shown below

the FOPTD model parameters are

$K=1$;$=5\mathrm{.}46$;$=0\mathrm{.}4$

$K=1$;$=6$;$=0\mathrm{.}8$

$K=1$;$=4\mathrm{.}46$;$=1\mathrm{.}42$

$K=1$;$=5$;$=1$