Finding the Fourth Proportional to 9,162.75, 12,643.52 and 5,129.80

Step by Step Solution

1. Step 1: Write the proportion equation
   9,162.75 : 12,643.52 = 5,129.80 : x
2. Step 2: Convert to fraction form
   9,162.75/12,643.52 = 5,129.80/x
3. Step 3: Cross multiply
   9,162.75x = 12,643.52 × 5,129.80
4. Step 4: Simplify right side
   9,162.75x = 64,858,710.11
5. Step 5: Solve for x
   x = 64,858,710.11/9,162.75
6. Step 6: Final answer
   x = 7,078.52