Finding the Fourth Proportional to 9,150.91, 12,628.31 and 5,172.39

Step by Step Solution

1. Step 1: Write the proportion equation
   9,150.91 : 12,628.31 = 5,172.39 : x
2. Step 2: Convert to fraction form
   9,150.91/12,628.31 = 5,172.39/x
3. Step 3: Cross multiply
   9,150.91x = 12,628.31 × 5,172.39
4. Step 4: Simplify right side
   9,150.91x = 65,318,518.50
5. Step 5: Solve for x
   x = 65,318,518.50/9,150.91
6. Step 6: Final answer
   x = 7,137.93