Finding the Fourth Proportional to 128,871.18, 177,843.20 and 71,510.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,871.18 : 177,843.20 = 71,510.72 : x
2. Step 2: Convert to fraction form
   128,871.18/177,843.20 = 71,510.72/x
3. Step 3: Cross multiply
   128,871.18x = 177,843.20 × 71,510.72
4. Step 4: Simplify right side
   128,871.18x = 12,717,694,032.33
5. Step 5: Solve for x
   x = 12,717,694,032.33/128,871.18
6. Step 6: Final answer
   x = 98,685.32