Finding the Fourth Proportional to 9,887.86, 13,645.43 and 5,639.41

Step by Step Solution

1. Step 1: Write the proportion equation
   9,887.86 : 13,645.43 = 5,639.41 : x
2. Step 2: Convert to fraction form
   9,887.86/13,645.43 = 5,639.41/x
3. Step 3: Cross multiply
   9,887.86x = 13,645.43 × 5,639.41
4. Step 4: Simplify right side
   9,887.86x = 76,952,174.40
5. Step 5: Solve for x
   x = 76,952,174.40/9,887.86
6. Step 6: Final answer
   x = 7,782.49