Do Now The ratio of men to women on a cruise is 6 to 8. If there are 168 people on the cruise, how many women are there?
More Difficult Proportions 1) 2)
3) 4)
5) 6)
Direct Variation If two variables vary directly, their ratio is constant. In other words, the variables increase or decrease proportionally. As one increases, so does the other. As one decreases, so does the other.
Examples Find each value if x and y vary directly. If y = 4 when x = 2, find y when x = 16. 2) If y = 9 when x = – 3, find x when y = 6.
If y = – 4.8 when x = – 1.6, find x when
Quiz Topics Solving Equations for a Variable Ratios and Proportions Word Problems Proportions with Distributing Direct Variation
If Mice Owned Computers...