$5.$ A polymerization plant produces $5,000$ tons of high$-$density polyethylene $($HDPE$)$ and $3,000$ tons of low$-$density polyethylene $($LDPE$)$ annually. If the density of HDPE is $0\mathrm{.}95$ g$/$cm$^3$ and the density of LDPE is $0\mathrm{.}92$ g$/$cm$^3,$ what is the total volume of polyethylene produced annually?

$6.$ In a catalytic reforming process, $2,000$ barrels of low$-$octane gasoline with a research octane number $($RON$)$ of $80$ are converted into $1,600$ barrels of high$-$octane gasoline with a RON of $95.$ What is the average RON of the blended gasoline?