Finding the Fourth Proportional to 12,429.86, 17,155.68 and 7,128.26

Step by Step Solution

1. Step 1: Write the proportion equation
   12,429.86 : 17,155.68 = 7,128.26 : x
2. Step 2: Convert to fraction form
   12,429.86/17,155.68 = 7,128.26/x
3. Step 3: Cross multiply
   12,429.86x = 17,155.68 × 7,128.26
4. Step 4: Simplify right side
   12,429.86x = 122,290,147.52
5. Step 5: Solve for x
   x = 122,290,147.52/12,429.86
6. Step 6: Final answer
   x = 9,838.42