Finding the Fourth Proportional to 86,085.75, 129,123.50 and 38,688.60

Step by Step Solution

1. Step 1: Write the proportion equation
   86,085.75 : 129,123.50 = 38,688.60 : x
2. Step 2: Convert to fraction form
   86,085.75/129,123.50 = 38,688.60/x
3. Step 3: Cross multiply
   86,085.75x = 129,123.50 × 38,688.60
4. Step 4: Simplify right side
   86,085.75x = 4,995,607,248.66
5. Step 5: Solve for x
   x = 4,995,607,248.66/86,085.75
6. Step 6: Final answer
   x = 58,030.59