NPV and IRR: Unequal Annual Net Cash Inflows

Rocky Road Company is evaluating a capital expenditure proposal that has the following predicted cash flows.

REQUIRED

a$.$ Determine the payback period.

Note: Round your answer to two decimal places. Enter $1\mathrm{.}251$ as $1\mathrm{.}25$; enter $1\mathrm{.}255$ as $1\mathrm{.}26.$

$x$ years

b$.$ Using a discount rate of $12\%,$ determine the net present value of the investment proposal.

Note: Round your answer to the nearest dollar.

$

c$.$ Determine the proposal's internal rate of return.

Note: Round your answer to two decimal places. Enter $10\mathrm{.}251\%$ as $10\mathrm{.}25\%$; enter $10\mathrm{.}255\%$ as $10\mathrm{.}26\%.$

$\%$