Finding the Fourth Proportional to 128,931.48, 177,925.68 and 72,342.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,931.48 : 177,925.68 = 72,342.72 : x
2. Step 2: Convert to fraction form
   128,931.48/177,925.68 = 72,342.72/x
3. Step 3: Cross multiply
   128,931.48x = 177,925.68 × 72,342.72
4. Step 4: Simplify right side
   128,931.48x = 12,871,627,649.05
5. Step 5: Solve for x
   x = 12,871,627,649.05/128,931.48
6. Step 6: Final answer
   x = 99,833.09