**Inversely proportional means that one variable goes up while the other goes down.**

**3 workers paint a house in 12 hours. How long would it have taken for 9 equally productive workers?**

**If Y is inversely proportional to X, the equation is of the form:**

**Y•X = k (where k is a constant). Y=k/X**

**Ratio Relationship of distance=speed·time**

**Speed and time are inversely proportional because as the speed increases, the time it takes to reach the destination decreases.**

**David travels 120 miles at 40 mph. How long does it take him?**

**Problem. If you were traveling 60 miles per hour, how far would you travel in one hour? Two hours? Three hours? ***Make a table and a chart showing the number of hours traveled vs. the number of miles traveled. How many hours did he travel at 45 miles per hour? *

**Inversely proportional Word problems**

**Example: Ice Cream Sales**** **

**Ice cream demand rises with temperature. When it gets too cold, sales go down.**

**PROBLEM: You want to determine the relationship between sales and temperature.**

**Example: Blanket Sales**