HP 10bII - Halting and Restarting IRR;YR; Entering a Guess for IRR;YR

= Case 5. The calculator displays: No Solution. There is no answer.
This situation might be the result of an error, such as a mistake in
keying in the cash flows. A common mistake that results in this
message is putting the wrong sign on a cash flow. A valid cash-flow
series for an IRR/YR calculation must have at least one positive and
one negative cash flow.
Halting and Restarting IRR/YR
The search for IRR/YR may take a relatively long time. You can halt the
calculation at any time by pressing the ©) key. The message Interrupted is
displayed. Pressing © now displays the current estimate for JRK/ YR.
You can resume the calculation by:
= Pressing COSI) СӘ while the current estimate is displayed in the
calculator line. This continues the calculation from where it left off.
в Storing a guess for IRR/YR, discussed below.
Entering a Guess for IRR/YR
То enter a guess, key in an estimate of JRR/YR and then press
OTTOS. You can enter a guess for IRR/YR at these times:
= Before beginning the calculation. A fairly accurate guess can reduce
the time required to calculate an answer and reduce the chance of
the calculator solving for an undesirable negative solution.
= After you've interrupted the calculation.
m After the calculator has halted the calculation due to any of the
aforementioned cases. However, for cases 3 and 5, no other
solutions will be found.
When calculating IRR/YR using a guess, the calculation halts when it
finds an answer. However, there may be additional positive or negative
answers, or no true solution at all. You can continue searching for
another solution by halting the calculation and entering а different guess.
One way to obtain a good guess for IRR/YR is to calculate the NPV for
various interest rates. Since IRR/ YR is the interest rate at which NPV
equals zero, the best estimate of IRR/YR is the interest rate that yields
the value for NPV closest to zero.
130 B: More About Calculations