Finding the Fourth Proportional to 7,172.30, 9,897.62 and 3,985.61

Step by Step Solution

1. Step 1: Write the proportion equation
   7,172.30 : 9,897.62 = 3,985.61 : x
2. Step 2: Convert to fraction form
   7,172.30/9,897.62 = 3,985.61/x
3. Step 3: Cross multiply
   7,172.30x = 9,897.62 × 3,985.61
4. Step 4: Simplify right side
   7,172.30x = 39,447,983.83
5. Step 5: Solve for x
   x = 39,447,983.83/7,172.30
6. Step 6: Final answer
   x = 5,500.05