Finding the Fourth Proportional to 9,128.47, 12,585.87 and 7,618.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,128.47 : 12,585.87 = 7,618.20 : x
2. Step 2: Convert to fraction form
   9,128.47/12,585.87 = 7,618.20/x
3. Step 3: Cross multiply
   9,128.47x = 12,585.87 × 7,618.20
4. Step 4: Simplify right side
   9,128.47x = 95,881,624.32
5. Step 5: Solve for x
   x = 95,881,624.32/9,128.47
6. Step 6: Final answer
   x = 10,503.59