Finding the Fourth Proportional to 21,891.56, 30,210.72 and 12,461

Step by Step Solution

1. Step 1: Write the proportion equation
   21,891.56 : 30,210.72 = 12,461 : x
2. Step 2: Convert to fraction form
   21,891.56/30,210.72 = 12,461/x
3. Step 3: Cross multiply
   21,891.56x = 30,210.72 × 12,461
4. Step 4: Simplify right side
   21,891.56x = 376,455,781.92
5. Step 5: Solve for x
   x = 376,455,781.92/21,891.56
6. Step 6: Final answer
   x = 17,196.39