$1.$ A contractor will use a packaged emulsion having a specific gravity of $1\mathrm{.}2$ and relative bulk strength of $155,$ to open an excavation in granite rock, sp$.$ Gr$.3\mathrm{.}5.$ The drilling equipment available will drill a $4-$in$.$ blasthole. The explosive come packaged in $3(1)/(2)-$in$.$ diameter sticks. What is the recommended burden distance for the first trial shot? Round the calculated burden distance to the nearest foot.