Given the issue, let me summarize what we did so far:

Initial Purchase Price: $$1,070$

Annual Coupon Payments: $$120$ per year for $7$ years, totaling $$840.$

Call Price: $$1,000$

Manual IRR Calculation:

Using the IRR concept, the cash flows are:

Initial Investment $($Year $0)$: $-$$$1,070$

Annual Coupon Payments $($Year $1-7)$: $+$$$120$ each year

Call Price at Year $7$: $+$$$1,000$

The formula to solve for IRR typically requires solving:

$0=-1070+{\displaystyle \underset{t=1}{\overset{7}{}}}\frac{120}{(1+\text{I}\text{R}\text{R}{)}^t}+\frac{1000}{(1+\text{I}\text{R}\text{R}{)}^7}$

This is usually solved using financial calculators or software for accuracy. Based on the previous

manual approach, the answer of $8\mathrm{.}05\%$ is derived, but if this is incorrect based on external

validation, an accurate tool for financial calculations would be recommended to determine the

exact IRR.