Finding the Fourth Proportional to 81,735, 121,887.24 and 80,987.63

Step by Step Solution

1. Step 1: Write the proportion equation
   81,735 : 121,887.24 = 80,987.63 : x
2. Step 2: Convert to fraction form
   81,735/121,887.24 = 80,987.63/x
3. Step 3: Cross multiply
   81,735x = 121,887.24 × 80,987.63
4. Step 4: Simplify right side
   81,735x = 9,871,358,085.41
5. Step 5: Solve for x
   x = 9,871,358,085.41/81,735
6. Step 6: Final answer
   x = 120,772.72