Create an interface named ISellable that contains two methods: SalesSpeech() and MakeSale(). In each RealEstateSalesperson and GirlScout class, implement SalesSpeech() to display an appropriate one-...

Create an interface named ISellable that contains two methods: SalesSpeech() and MakeSale(). In each RealEstateSalesperson and GirlScout class, implement SalesSpeech() to display an appropriate one- or two-sentence sales speech that the objects of the class could use.

In the RealEstateSalesperson class, implement the MakeSale() method to accept an integer dollar value for a house, add the value to the RealEstateSalesperson’s total value sold, and compute the total commission earned.

In the GirlScout class, implement the MakeSale() method to accept an integer representing the number of boxes of cookies sold and add it to the total field.