Section 1: Introduction and Converting from Fraction to Percent Form

A percent is a ratio (fraction) whose denominator is 100.

To convert a fraction to percent form, form a proportion by setting the fraction equal to and solve for P.

Example:

Write 5/8 in percent form.
  Solution: Set the fraction equal to P/100 and solve for P: 

Solve by setting cross products equal to each other.

500 = 8P

Divide by 8:

P = = 67.5

5/8 = 67.5%

To convert from percent form to fraction form:

Drop the percent sign and place the value over 100. Then simplify the fraction.

Example:

Write 55% in fraction form.

Solution:

55% = 

Reduce the fraction:

 = 

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