In the worksheet Sales, the user will only input data in cells highlighted in yellow colour, in order to save the time in data entry and avoid input error. You are required to design formulae for all cells in four columns (Category, Price, Total and Cash), so that the correct data (e.g. Price, Total etc.) will be displayed automatically when the necessary input data is entered. Also, in this worksheet, apply the skills you have learned in Excel to check the input data.