Finding the Fourth Proportional to 31,789.32, 47,678.58 and 8,418.12

Step by Step Solution

1. Step 1: Write the proportion equation
   31,789.32 : 47,678.58 = 8,418.12 : x
2. Step 2: Convert to fraction form
   31,789.32/47,678.58 = 8,418.12/x
3. Step 3: Cross multiply
   31,789.32x = 47,678.58 × 8,418.12
4. Step 4: Simplify right side
   31,789.32x = 401,364,007.87
5. Step 5: Solve for x
   x = 401,364,007.87/31,789.32
6. Step 6: Final answer
   x = 12,625.75