Finding the Fourth Proportional to 12,891.50, 17,788.71 and 7,224.95

Step by Step Solution

1. Step 1: Write the proportion equation
   12,891.50 : 17,788.71 = 7,224.95 : x
2. Step 2: Convert to fraction form
   12,891.50/17,788.71 = 7,224.95/x
3. Step 3: Cross multiply
   12,891.50x = 17,788.71 × 7,224.95
4. Step 4: Simplify right side
   12,891.50x = 128,522,511.82
5. Step 5: Solve for x
   x = 128,522,511.82/12,891.50
6. Step 6: Final answer
   x = 9,969.55