Finding the Fourth Proportional to 85,989.61, 128,097.59 and 83,378.17

Step by Step Solution

1. Step 1: Write the proportion equation
   85,989.61 : 128,097.59 = 83,378.17 : x
2. Step 2: Convert to fraction form
   85,989.61/128,097.59 = 83,378.17/x
3. Step 3: Cross multiply
   85,989.61x = 128,097.59 × 83,378.17
4. Step 4: Simplify right side
   85,989.61x = 10,680,542,635.61
5. Step 5: Solve for x
   x = 10,680,542,635.61/85,989.61
6. Step 6: Final answer
   x = 124,207.36