Finding the Fourth Proportional to 9,008.60, 12,428.55 and 5,231.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,008.60 : 12,428.55 = 5,231.30 : x
2. Step 2: Convert to fraction form
   9,008.60/12,428.55 = 5,231.30/x
3. Step 3: Cross multiply
   9,008.60x = 12,428.55 × 5,231.30
4. Step 4: Simplify right side
   9,008.60x = 65,017,411.47
5. Step 5: Solve for x
   x = 65,017,411.47/9,008.60
6. Step 6: Final answer
   x = 7,217.26