Finding the Fourth Proportional to 12,782.52, 17,639.40 and 7,117.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,782.52 : 17,639.40 = 7,117.50 : x
2. Step 2: Convert to fraction form
   12,782.52/17,639.40 = 7,117.50/x
3. Step 3: Cross multiply
   12,782.52x = 17,639.40 × 7,117.50
4. Step 4: Simplify right side
   12,782.52x = 125,548,429.50
5. Step 5: Solve for x
   x = 125,548,429.50/12,782.52
6. Step 6: Final answer
   x = 9,821.88