Finding the Fourth Proportional to 9,320.28, 12,861.90 and 5,128.53

Step by Step Solution

1. Step 1: Write the proportion equation
   9,320.28 : 12,861.90 = 5,128.53 : x
2. Step 2: Convert to fraction form
   9,320.28/12,861.90 = 5,128.53/x
3. Step 3: Cross multiply
   9,320.28x = 12,861.90 × 5,128.53
4. Step 4: Simplify right side
   9,320.28x = 65,962,640.01
5. Step 5: Solve for x
   x = 65,962,640.01/9,320.28
6. Step 6: Final answer
   x = 7,077.32