Finding the Fourth Proportional to 128,878.17, 177,851.50 and 71,526.15

Step by Step Solution

1. Step 1: Write the proportion equation
   128,878.17 : 177,851.50 = 71,526.15 : x
2. Step 2: Convert to fraction form
   128,878.17/177,851.50 = 71,526.15/x
3. Step 3: Cross multiply
   128,878.17x = 177,851.50 × 71,526.15
4. Step 4: Simplify right side
   128,878.17x = 12,721,033,066.73
5. Step 5: Solve for x
   x = 12,721,033,066.73/128,878.17
6. Step 6: Final answer
   x = 98,705.88