Finding the Fourth Proportional to 9,906.75, 13,671.72 and 5,715

Step by Step Solution

1. Step 1: Write the proportion equation
   9,906.75 : 13,671.72 = 5,715 : x
2. Step 2: Convert to fraction form
   9,906.75/13,671.72 = 5,715/x
3. Step 3: Cross multiply
   9,906.75x = 13,671.72 × 5,715
4. Step 4: Simplify right side
   9,906.75x = 78,133,879.80
5. Step 5: Solve for x
   x = 78,133,879.80/9,906.75
6. Step 6: Final answer
   x = 7,886.93