Finding the Fourth Proportional to 9,918.72, 13,687.98 and 5,442.40

Step by Step Solution

1. Step 1: Write the proportion equation
   9,918.72 : 13,687.98 = 5,442.40 : x
2. Step 2: Convert to fraction form
   9,918.72/13,687.98 = 5,442.40/x
3. Step 3: Cross multiply
   9,918.72x = 13,687.98 × 5,442.40
4. Step 4: Simplify right side
   9,918.72x = 74,495,462.35
5. Step 5: Solve for x
   x = 74,495,462.35/9,918.72
6. Step 6: Final answer
   x = 7,510.59