Finding the Fourth Proportional to 81,139.50, 121,728.69 and 25,735.50

Step by Step Solution

1. Step 1: Write the proportion equation
   81,139.50 : 121,728.69 = 25,735.50 : x
2. Step 2: Convert to fraction form
   81,139.50/121,728.69 = 25,735.50/x
3. Step 3: Cross multiply
   81,139.50x = 121,728.69 × 25,735.50
4. Step 4: Simplify right side
   81,139.50x = 3,132,748,701.50
5. Step 5: Solve for x
   x = 3,132,748,701.50/81,139.50
6. Step 6: Final answer
   x = 38,609.42