Finding the Fourth Proportional to 12,807.69, 17,671.61 and 7,771.79

Step by Step Solution

1. Step 1: Write the proportion equation
   12,807.69 : 17,671.61 = 7,771.79 : x
2. Step 2: Convert to fraction form
   12,807.69/17,671.61 = 7,771.79/x
3. Step 3: Cross multiply
   12,807.69x = 17,671.61 × 7,771.79
4. Step 4: Simplify right side
   12,807.69x = 137,340,041.88
5. Step 5: Solve for x
   x = 137,340,041.88/12,807.69
6. Step 6: Final answer
   x = 10,723.25