You must have enjoyed the design process.
The weather Charts, Graphs, Graphics and use of formulas.
The linked cells and Conditional formatted cells
The search of different types of phones to match the prices.
The search of prices the match the model given.
All these formative activities were to prepare you for the design process.
You did two designed and analyzed each against the design specs.
You finally selected one and Justified why you though this was the best.
Now is the time to apply the skills to you project.
The Design Summative will be used to guide the process.