Percent as fraction
part/total = %
% * total = part
part/% = total
if given in percents units for absolute change are percentage points
Absolute and Relative difference
not absolute change
percentage more than; percentage less than
larger-smaller/the quantity after "than"
Increasing or decreasing by a percent
# * (1 + .%) = Pecent increase
# * (1 - .%)= Percent decrease
Successive percentage change
multiple increases or decreases in percent
org # * (1 +or- .%) = X
X * (1 +or- .%) =Y
continue as needed
Solve for Original
Finding original # that has been reduced = new/(1-.%)
Finding original # that has been increased = new/(1+.%)
1st #/ 2nd #
percent more or less than
Assuming A=5; B=4
A is what percent more than B =25% more
B is what percent less than A =20% less
Assuming A=5; B=4
A is what percent of B = 125%
B is what percent of A = 80%
Rate per 10,000
Example death rates of hunting
600 deaths/2000000 hunters = .0003
.0003*10,000 = 3
3 deaths per 10,000 participants
y = mx + b
where m=slope or rate of change
b= y intercept or inital value
yintercept or inital value= y value when x equals 0
Rate of change formula?
y = P*(1+or-r)^x
Where P = inital value(value of y when x = 0)
r = percent change (in decimal form)
x = independent variable (usually time)
y = dependent variable
For an increase of 1 in x, y increases or decreases by a constant percent change.
as the x variable increases by 1, the y variable increases or decreases by a certain amount (rate of change)
Finding ratio of CPI?
new years CPI/old years CPI = CPI ratio
Converting to constant dollars?
X dollars in old year is worth how much in new year constant dollars
new year CPI/ old year CPI * X dollars = X dollars in new year constant dollars
Annual Inflation rate?
Percentage change in the CPI in one year from previous year
1996 CPI-1995CPI/1995 CPI = Inflation rate
162.6-157.9/157.9 = 3.0% inflation rate for 1996
Finding monthly payments using excel?
fx icon in formula bar
drop down menu > finacial > PMT > box appears
Enter rate = APR (as a decimal) divided by 12
Enter NPer (total # of payments)= # of years *12
Enter Pv (principal) = amount of loan as negative # no commas
Absolute cell reference?
used to lock in a cell reference in a formula when working on tables so that as formula moves down the table it still refers to correct cell.
enter cell reference than hit F4 button