Question $4(2$ points$)$

The hand sanitizer business was booming in $2020.$ Whereas the industry made $$200$

million in $2019,$ this number jumped to $$1\mathrm{.}4$ billion in $2020.$ Industry analysts suggest

that the same percent change happened for multi$-$purpose cleaners between $2019$

and $2020.$ If the total revenue made by the multi$-$purpose cleaner industry was $$3\mathrm{.}5$

billion in $2020,$ what was the revenue made by this industry in $2019?$

$$500$ million

$$800$ million

$$400$ million

$$600$ million