Excel Formula Help

Ok, If you do not have 365 then the below two formula will work in any version of Excel
both formulas below are array formula. so it cannot work if it is just entered.
when you enter the formula, Plz hold keyboard CONTROL SHIFT & ENTER.

For lowest put this and drag down

=MIN(IF($A$4:$A$14=A18,$B$4:$B$14))

and for highest put below formula and drag down

=MAX(IF($A$4:$A$14=A18,$B$4:$B$14))

If you do not like the control shift enter.

then if you have Excel 2010 or above then the following formulas will work just without the need of special keystroke.

For lowest

=AGGREGATE(14,6,$B$4:$B$14/(($A$4:$A$14=A18)*($B$4:$B$14>0)),1)

for Highest

=AGGREGATE(15,6,$B$4:$B$14/(($A$4:$A$14=A18)*($B$4:$B$14>0)),1)