Apple iWork '09 - Manual (Page 343)

Chapter 13 Additional Examples and Topics 343
depr-period
Certain functions return the amount of depreciation for a specified period. depr-period is used to
specify the period.
depr-period is specified as a number representing the desired depreciation period using the same
time frame (for example, monthly, quarterly, or annually) as life.
Assume that you purchase a new digital photocopy machine for your office. The purchase price of
the photocopy machine was $2,625 with tax. The vendor charged $100 to deliver and set it up. The
photocopy machine is expected to be used for 4 years, at which time it is expected to have a resale
value of $400. If you wished to determine the depreciation for the third year, depr-period would be 3.
effective-int-rate
Annuities and investments have an effective interest rate, which is calculated using the nominal
(stated or coupon) rate and the number of interest payments per year.
effective-int-rate is specified as a decimal number and must be greater than 0.
Assume that you own a security with a face value of $1,000,000 that pays annual interest of 4.5%
based on the face value, on a quarterly basis, which is an effective rate of approximately 4.58%.
effective-int-rate would be 0.0458. See also the description of nominal-rate and num-periods-year.
end-per
Certain functions return principal or interest for a series of specified payments. end-per is used to
indicate the last payment to be included in the value returned. See also the discussion of start-per.
end-per is specified as a number and must be greater than 0.
Assume that you are purchasing a home. The mortgage broker offers you a loan with an initial
balance of $200,000, a term of 10 years, an annual interest rate of 6.0%, fixed monthly payments of
$1070.45, and a balance to be refinanced at maturity of $100,000. If you wished to know the total
amount of interest paid in the third year, start-per would be 25 and end-per would be 36.
estimate
An estimate of the expected outcome is used by some financial functions.
estimate is specified as a decimal number. For example, 13% is specified as 0.13. estimate can be
negative, if a loss is expected. If estimate is not specified, 0.10 is used as the default value.
If you do not have an idea as to the expected outcome and the default value does not result in
a solution, initially try a larger positive estimate. If this does not result in an outcome, try a small
negative estimate.
frequency
An investment may pay interest on a periodic basis. frequency is used to indicate how often interest
is paid.
frequency is the number 1, 2, or 4.
 A value of 1 indicates that the investment pays interest annually (once a year).
 A value of 2 indicates that the investment pays interest semiannually (twice per year).
 A value of 4 indicates that the investment pays interest quarterly (four times per year).
Assume that you are evaluating a corporate bond that pays interest quarterly. frequency would be 4.
Or assume you are evaluating a government bond that pays interest semiannually. frequency would
be 2.