Finding the Fourth Proportional to 21,928.86, 30,261.69 and 12,497.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,928.86 : 30,261.69 = 12,497.31 : x
2. Step 2: Convert to fraction form
   21,928.86/30,261.69 = 12,497.31/x
3. Step 3: Cross multiply
   21,928.86x = 30,261.69 × 12,497.31
4. Step 4: Simplify right side
   21,928.86x = 378,189,721.05
5. Step 5: Solve for x
   x = 378,189,721.05/21,928.86
6. Step 6: Final answer
   x = 17,246.21