Leonards company purchases a window hardware from Williams Hardware Co and sells to the market. Leonard is also considering manufacturing the product internally. Williams Hardware Co$.$ charges $$4$ per unit, with a minimum order of $3,000$ units. If Leonard manufactures the product in$-$home, the process setup fee could be $$15,000$ and then $$1\mathrm{.}82$ per unit for labor and materials.a$)$ Draw a graph illustrating the crossover $($or indifference$)$ point.b$)$ Determine the number of units where either choice has the same cost.