Finding the Fourth Proportional to 13,399.02, 20,101.91 and 7,857

Step by Step Solution

1. Step 1: Write the proportion equation
   13,399.02 : 20,101.91 = 7,857 : x
2. Step 2: Convert to fraction form
   13,399.02/20,101.91 = 7,857/x
3. Step 3: Cross multiply
   13,399.02x = 20,101.91 × 7,857
4. Step 4: Simplify right side
   13,399.02x = 157,940,667.59
5. Step 5: Solve for x
   x = 157,940,667.59/13,399.02
6. Step 6: Final answer
   x = 11,787.48