Finding the Fourth Proportional to 171,432.14, 256,978.69 and 81,316.81

Step by Step Solution

1. Step 1: Write the proportion equation
   171,432.14 : 256,978.69 = 81,316.81 : x
2. Step 2: Convert to fraction form
   171,432.14/256,978.69 = 81,316.81/x
3. Step 3: Cross multiply
   171,432.14x = 256,978.69 × 81,316.81
4. Step 4: Simplify right side
   171,432.14x = 20,896,687,308.78
5. Step 5: Solve for x
   x = 20,896,687,308.78/171,432.14
6. Step 6: Final answer
   x = 121,894.81