Finding the Fourth Proportional to 9,665.90, 13,340.06 and 5,418.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,665.90 : 13,340.06 = 5,418.12 : x
2. Step 2: Convert to fraction form
   9,665.90/13,340.06 = 5,418.12/x
3. Step 3: Cross multiply
   9,665.90x = 13,340.06 × 5,418.12
4. Step 4: Simplify right side
   9,665.90x = 72,278,045.89
5. Step 5: Solve for x
   x = 72,278,045.89/9,665.90
6. Step 6: Final answer
   x = 7,477.63