Finding the Fourth Proportional to 9,915.97, 13,684.12 and 5,439.69

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915.97 : 13,684.12 = 5,439.69 : x
2. Step 2: Convert to fraction form
   9,915.97/13,684.12 = 5,439.69/x
3. Step 3: Cross multiply
   9,915.97x = 13,684.12 × 5,439.69
4. Step 4: Simplify right side
   9,915.97x = 74,437,370.72
5. Step 5: Solve for x
   x = 74,437,370.72/9,915.97
6. Step 6: Final answer
   x = 7,506.82