Finding the Fourth Proportional to 4,188.10, 6,276.72 and 3,139.86

Step by Step Solution

1. Step 1: Write the proportion equation
   4,188.10 : 6,276.72 = 3,139.86 : x
2. Step 2: Convert to fraction form
   4,188.10/6,276.72 = 3,139.86/x
3. Step 3: Cross multiply
   4,188.10x = 6,276.72 × 3,139.86
4. Step 4: Simplify right side
   4,188.10x = 19,708,022.06
5. Step 5: Solve for x
   x = 19,708,022.06/4,188.10
6. Step 6: Final answer
   x = 4,705.72