Finding the Fourth Proportional to 105,142.16, 144,727.88 and 91,689.68

Step by Step Solution

1. Step 1: Write the proportion equation
   105,142.16 : 144,727.88 = 91,689.68 : x
2. Step 2: Convert to fraction form
   105,142.16/144,727.88 = 91,689.68/x
3. Step 3: Cross multiply
   105,142.16x = 144,727.88 × 91,689.68
4. Step 4: Simplify right side
   105,142.16x = 13,270,053,004.28
5. Step 5: Solve for x
   x = 13,270,053,004.28/105,142.16
6. Step 6: Final answer
   x = 126,210.58