1. The problem is to find the sum of 3.68 and 1.74. 2. The formula for addition is simply $a + b = c$ where $a$ and $b$ are the numbers to add. 3. Add the numbers: $3.68 + 1.74 = 5.42$. 4. Therefore, the sum of 3.68 and 1.74 is $5.42$.