Finding the Fourth Proportional to 8,591.31, 12,945.49 and 7,065.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,591.31 : 12,945.49 = 7,065.50 : x
2. Step 2: Convert to fraction form
   8,591.31/12,945.49 = 7,065.50/x
3. Step 3: Cross multiply
   8,591.31x = 12,945.49 × 7,065.50
4. Step 4: Simplify right side
   8,591.31x = 91,466,277.20
5. Step 5: Solve for x
   x = 91,466,277.20/8,591.31
6. Step 6: Final answer
   x = 10,646.37