1. 8.1 Direct Variation.notebook March 18, 2013
Direct Variation and Proportion
The water pressure, y on a scuba diver Depth Pressure y
x
increases with the diver's depth x meters x (m) y (kPa)
beneath the surface.
3 29.4 9.8
6 58.8
9 88.2
12 117.6

2. 8.1 Direct Variation.notebook March 18, 2013
Hours (x) Pay (y)
2 15
y 3 22.5
k = x direct variation 4 30
If you work 12 hours, how much money will you make?

3. 8.1 Direct Variation.notebook March 18, 2013
If y varies directly as x, and y = 15 when x = 24, find x when y = 25.
If y is directly proportional to x2 and y = 12 when x = 4 find y when x = 6.

4. 8.1 Direct Variation.notebook March 18, 2013
The amount of hydrogen produced when sodium is added to water varies
directly as the amount of sodium added. If 92 g of sodium produces 4 g
of hydrogen find the amount of sodium needed to produce 10 g of hydrogen.