Finding the Fourth Proportional to 105,372.16, 157,891.78 and 85,553.89

Step by Step Solution

1. Step 1: Write the proportion equation
   105,372.16 : 157,891.78 = 85,553.89 : x
2. Step 2: Convert to fraction form
   105,372.16/157,891.78 = 85,553.89/x
3. Step 3: Cross multiply
   105,372.16x = 157,891.78 × 85,553.89
4. Step 4: Simplify right side
   105,372.16x = 13,508,255,978.02
5. Step 5: Solve for x
   x = 13,508,255,978.02/105,372.16
6. Step 6: Final answer
   x = 128,195.68