Finding the Fourth Proportional to 39,131.78, 58,685.31 and 12,830.36

Step by Step Solution

1. Step 1: Write the proportion equation
   39,131.78 : 58,685.31 = 12,830.36 : x
2. Step 2: Convert to fraction form
   39,131.78/58,685.31 = 12,830.36/x
3. Step 3: Cross multiply
   39,131.78x = 58,685.31 × 12,830.36
4. Step 4: Simplify right side
   39,131.78x = 752,953,360.59
5. Step 5: Solve for x
   x = 752,953,360.59/39,131.78
6. Step 6: Final answer
   x = 19,241.48