Finding the Fourth Proportional to 128,513.78, 177,348.98 and 71,925.15

Step by Step Solution

1. Step 1: Write the proportion equation
   128,513.78 : 177,348.98 = 71,925.15 : x
2. Step 2: Convert to fraction form
   128,513.78/177,348.98 = 71,925.15/x
3. Step 3: Cross multiply
   128,513.78x = 177,348.98 × 71,925.15
4. Step 4: Simplify right side
   128,513.78x = 12,755,851,629.22
5. Step 5: Solve for x
   x = 12,755,851,629.22/128,513.78
6. Step 6: Final answer
   x = 99,256.69