Finding the Fourth Proportional to 12,071.50, 16,658.72 and 7,039.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,071.50 : 16,658.72 = 7,039.20 : x
2. Step 2: Convert to fraction form
   12,071.50/16,658.72 = 7,039.20/x
3. Step 3: Cross multiply
   12,071.50x = 16,658.72 × 7,039.20
4. Step 4: Simplify right side
   12,071.50x = 117,264,061.82
5. Step 5: Solve for x
   x = 117,264,061.82/12,071.50
6. Step 6: Final answer
   x = 9,714.13