Finding the Fourth Proportional to 3,156.57, 4,321.15 and 3,149.28

Step by Step Solution

1. Step 1: Write the proportion equation
   3,156.57 : 4,321.15 = 3,149.28 : x
2. Step 2: Convert to fraction form
   3,156.57/4,321.15 = 3,149.28/x
3. Step 3: Cross multiply
   3,156.57x = 4,321.15 × 3,149.28
4. Step 4: Simplify right side
   3,156.57x = 13,608,503.40
5. Step 5: Solve for x
   x = 13,608,503.40/3,156.57
6. Step 6: Final answer
   x = 4,311.17