Finding the Fourth Proportional to 12,784.20, 17,640.93 and 9,428.82

Step by Step Solution

1. Step 1: Write the proportion equation
   12,784.20 : 17,640.93 = 9,428.82 : x
2. Step 2: Convert to fraction form
   12,784.20/17,640.93 = 9,428.82/x
3. Step 3: Cross multiply
   12,784.20x = 17,640.93 × 9,428.82
4. Step 4: Simplify right side
   12,784.20x = 166,333,153.60
5. Step 5: Solve for x
   x = 166,333,153.60/12,784.20
6. Step 6: Final answer
   x = 13,010.84