Finding the Fourth Proportional to 12,499.25, 18,748.39 and 3,139.34

Step by Step Solution

1. Step 1: Write the proportion equation
   12,499.25 : 18,748.39 = 3,139.34 : x
2. Step 2: Convert to fraction form
   12,499.25/18,748.39 = 3,139.34/x
3. Step 3: Cross multiply
   12,499.25x = 18,748.39 × 3,139.34
4. Step 4: Simplify right side
   12,499.25x = 58,857,570.66
5. Step 5: Solve for x
   x = 58,857,570.66/12,499.25
6. Step 6: Final answer
   x = 4,708.89