Finding the Fourth Proportional to 171,855.09, 257,749.25 and 86,443.20

Step by Step Solution

1. Step 1: Write the proportion equation
   171,855.09 : 257,749.25 = 86,443.20 : x
2. Step 2: Convert to fraction form
   171,855.09/257,749.25 = 86,443.20/x
3. Step 3: Cross multiply
   171,855.09x = 257,749.25 × 86,443.20
4. Step 4: Simplify right side
   171,855.09x = 22,280,669,535.38
5. Step 5: Solve for x
   x = 22,280,669,535.38/171,855.09
6. Step 6: Final answer
   x = 129,648.00