Finding the Fourth Proportional to 9,128.90, 12,591.96 and 5,769.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,128.90 : 12,591.96 = 5,769.12 : x
2. Step 2: Convert to fraction form
   9,128.90/12,591.96 = 5,769.12/x
3. Step 3: Cross multiply
   9,128.90x = 12,591.96 × 5,769.12
4. Step 4: Simplify right side
   9,128.90x = 72,644,553.86
5. Step 5: Solve for x
   x = 72,644,553.86/9,128.90
6. Step 6: Final answer
   x = 7,957.64