Finding the Fourth Proportional to 9,911.87, 13,677.40 and 5,721.47

Step by Step Solution

1. Step 1: Write the proportion equation
   9,911.87 : 13,677.40 = 5,721.47 : x
2. Step 2: Convert to fraction form
   9,911.87/13,677.40 = 5,721.47/x
3. Step 3: Cross multiply
   9,911.87x = 13,677.40 × 5,721.47
4. Step 4: Simplify right side
   9,911.87x = 78,254,805.17
5. Step 5: Solve for x
   x = 78,254,805.17/9,911.87
6. Step 6: Final answer
   x = 7,895.06