They have asked for an average track
and, strictly speaking, it should be measured at the mid-point.
However, this is a relatively short
and predominantly North/South track so there will be very little difference
between the initial and mean track.
Having drawn the line from CRK to CRN
put the protractor over CRK and align it with magnetic
North (the 053ēM and 353ēM radials on the chart will help with this
alignment).
Note the track CRK-CRN is
357ēM.
With compasses/dividers measure the
distance CRK-CRN using the latitude scale: 89
NM.
Alternatively, go for the application
of common sense and note that the track is a bit more than 353ēM (CRK-SHA) and
there is only one feasible option.