Finding the Fourth Proportional to 9,128.57, 12,597.86 and 5,591.97

Step by Step Solution

1. Step 1: Write the proportion equation
   9,128.57 : 12,597.86 = 5,591.97 : x
2. Step 2: Convert to fraction form
   9,128.57/12,597.86 = 5,591.97/x
3. Step 3: Cross multiply
   9,128.57x = 12,597.86 × 5,591.97
4. Step 4: Simplify right side
   9,128.57x = 70,446,869.16
5. Step 5: Solve for x
   x = 70,446,869.16/9,128.57
6. Step 6: Final answer
   x = 7,717.19