Finding the Fourth Proportional to 9,902.61, 13,665.29 and 5,711.49

Step by Step Solution

1. Step 1: Write the proportion equation
   9,902.61 : 13,665.29 = 5,711.49 : x
2. Step 2: Convert to fraction form
   9,902.61/13,665.29 = 5,711.49/x
3. Step 3: Cross multiply
   9,902.61x = 13,665.29 × 5,711.49
4. Step 4: Simplify right side
   9,902.61x = 78,049,138.62
5. Step 5: Solve for x
   x = 78,049,138.62/9,902.61
6. Step 6: Final answer
   x = 7,881.67