Finding the Fourth Proportional to 12,271.75, 18,405.20 and 3,505.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,271.75 : 18,405.20 = 3,505.12 : x
2. Step 2: Convert to fraction form
   12,271.75/18,405.20 = 3,505.12/x
3. Step 3: Cross multiply
   12,271.75x = 18,405.20 × 3,505.12
4. Step 4: Simplify right side
   12,271.75x = 64,512,417.10
5. Step 5: Solve for x
   x = 64,512,417.10/12,271.75
6. Step 6: Final answer
   x = 5,256.99