Q$20)$ A sewer pipe must be laid from a starting invert elevations of $650\mathrm{.}73ft$ at station $9+25$ to and ending invert elevation $653\mathrm{.}81ft$ at station $12+75.$ Determine the uniform grade needed, and calculate invert elevations at each $50-ft$ station. $(5$ pts$)$

$\backslash$table$[[$Station$,$Increment,Elevation$],[9+25,,],[9+50,,],[10+00,,],[10+50,,],[11+50,,],[12+00,,],[12+50,,],[12+75,,]]$

Q$21)$ True or False: $1$ acre $=43,650$ square feet $(2$ pts