Finding the Fourth Proportional to 12,783.57, 17,640.59 and 7,117.89

Step by Step Solution

1. Step 1: Write the proportion equation
   12,783.57 : 17,640.59 = 7,117.89 : x
2. Step 2: Convert to fraction form
   12,783.57/17,640.59 = 7,117.89/x
3. Step 3: Cross multiply
   12,783.57x = 17,640.59 × 7,117.89
4. Step 4: Simplify right side
   12,783.57x = 125,563,743.57
5. Step 5: Solve for x
   x = 125,563,743.57/12,783.57
6. Step 6: Final answer
   x = 9,822.28