Finding the Fourth Proportional to 4,105.84, 6,154.20 and 3,128.72

Step by Step Solution

1. Step 1: Write the proportion equation
   4,105.84 : 6,154.20 = 3,128.72 : x
2. Step 2: Convert to fraction form
   4,105.84/6,154.20 = 3,128.72/x
3. Step 3: Cross multiply
   4,105.84x = 6,154.20 × 3,128.72
4. Step 4: Simplify right side
   4,105.84x = 19,254,768.62
5. Step 5: Solve for x
   x = 19,254,768.62/4,105.84
6. Step 6: Final answer
   x = 4,689.61