Finding the Fourth Proportional to 128,410.56, 177,196.95 and 71,811

Step by Step Solution

1. Step 1: Write the proportion equation
   128,410.56 : 177,196.95 = 71,811 : x
2. Step 2: Convert to fraction form
   128,410.56/177,196.95 = 71,811/x
3. Step 3: Cross multiply
   128,410.56x = 177,196.95 × 71,811
4. Step 4: Simplify right side
   128,410.56x = 12,724,690,176.45
5. Step 5: Solve for x
   x = 12,724,690,176.45/128,410.56
6. Step 6: Final answer
   x = 99,093.80