Finding the Fourth Proportional to 12,821.45, 17,693.61 and 7,078.91

Step by Step Solution

1. Step 1: Write the proportion equation
   12,821.45 : 17,693.61 = 7,078.91 : x
2. Step 2: Convert to fraction form
   12,821.45/17,693.61 = 7,078.91/x
3. Step 3: Cross multiply
   12,821.45x = 17,693.61 × 7,078.91
4. Step 4: Simplify right side
   12,821.45x = 125,251,384.30
5. Step 5: Solve for x
   x = 125,251,384.30/12,821.45
6. Step 6: Final answer
   x = 9,768.90