Finding the Fourth Proportional to 21,818.76, 30,109.50 and 12,387.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,818.76 : 30,109.50 = 12,387.12 : x
2. Step 2: Convert to fraction form
   21,818.76/30,109.50 = 12,387.12/x
3. Step 3: Cross multiply
   21,818.76x = 30,109.50 × 12,387.12
4. Step 4: Simplify right side
   21,818.76x = 372,969,989.64
5. Step 5: Solve for x
   x = 372,969,989.64/21,818.76
6. Step 6: Final answer
   x = 17,094.00