El Dorado mine is evaluating a new gold mine.

Cash flows given:

Year $1$: $63,000,000$

Year $2$: $85,000,000$

Year $3$: $120,000,000$

Year $4$: $145,000,000$

Year $5$: $175,000,000$

Year $6$: $120,000,000$

Year $7$: $95,000,000$

Year $8$: $75,000,000$

Cost of opening today: $$500$ million

Cash outflow of $$100$ million in nine yesrs from today in costs associated with closing the mine.

The mine requires a $10\%$ required return.

Question:

$1.$ Construct a spreadsheet to calculate payback period, internal rate of return, and net present value of the proposed mine.