Extra$-$Credit:

$[$W$]$ What if$,$ in reality, the average size of galaxies were smaller than $70$ kly$?$ How would this affect your measurement? Would your estimate of the Hubble constant assuming $D=70kly$ be an underestimate or an overestimate? Would your estimate of the age of the Universe be overestimated or underestimated? Justify your answer with a few sentences, and $($if possible$)$ a careful sketch.