Chapter 4 - Proportions, Percents, and Solving Inequalities - 4.1 - Ratios and Proportions - Problem Set 4.1 - Page 148: 6

11.4 liters of paint are required.

We need to convert 3 gallons to liters. To do this, we multiply 3 gallons by the ratio that converts gallons to liters. The ratio that converts gallons to liters is $\frac{3.8\ liters}{1\ gallon}$. So, 3 gallons $\times$ $\frac{3.8\ liters}{1\ gallon}$ = 11.4 liters. So, 11.4 liters of paint are required.