5. PROPORTIONS ARE GENERALLY SOLVED BY CROSS-MULTIPLYING (MUL-TIPLY DI...

5

. Proportions are generally solved by cross-multiplying (mul-tiply diagonally and set the cross-products equal to each other). For example,x

2

5

=

2

5

(2)(25) = 5x50 = 5x10 = xPercents are always “out of 100.” 45% means 45 out of 100. It is important to be able to write percentsas decimals. This is done by moving the decimal point two places to the left.45% = 0.453% = 0.03124% = 1.240.9% = 0.009P

ROBABILITY

favorable

The probability of an event is P(event)= .For example, the probability of rolling a 5 when rolling a 6-sided die is

1