Consider: $($a$)$ Stock trades for $$100$; $($b$)$ Puts with exercise prices of $$90,$ $$100,$ and $$110$ trade at prices of $$3\mathrm{.}26,$ $$7\mathrm{.}73,$ and $$13\mathrm{.}58$ respectively. If a person buys a $$110$ put and writes a $$90$ put, at what price will she break even? Please answer correctly up to two decimal places.