Finding the Fourth Proportional to 11,385.04, 17,085.18 and 3,989.50

Step by Step Solution

1. Step 1: Write the proportion equation
   11,385.04 : 17,085.18 = 3,989.50 : x
2. Step 2: Convert to fraction form
   11,385.04/17,085.18 = 3,989.50/x
3. Step 3: Cross multiply
   11,385.04x = 17,085.18 × 3,989.50
4. Step 4: Simplify right side
   11,385.04x = 68,161,325.61
5. Step 5: Solve for x
   x = 68,161,325.61/11,385.04
6. Step 6: Final answer
   x = 5,986.92