Finding the Fourth Proportional to 9,415.80, 12,983.20 and 7,709

Step by Step Solution

1. Step 1: Write the proportion equation
   9,415.80 : 12,983.20 = 7,709 : x
2. Step 2: Convert to fraction form
   9,415.80/12,983.20 = 7,709/x
3. Step 3: Cross multiply
   9,415.80x = 12,983.20 × 7,709
4. Step 4: Simplify right side
   9,415.80x = 100,087,488.80
5. Step 5: Solve for x
   x = 100,087,488.80/9,415.80
6. Step 6: Final answer
   x = 10,629.74