Finding the Fourth Proportional to 82,458, 123,687.81 and 20,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   82,458 : 123,687.81 = 20,128.50 : x
2. Step 2: Convert to fraction form
   82,458/123,687.81 = 20,128.50/x
3. Step 3: Cross multiply
   82,458x = 123,687.81 × 20,128.50
4. Step 4: Simplify right side
   82,458x = 2,489,650,083.59
5. Step 5: Solve for x
   x = 2,489,650,083.59/82,458
6. Step 6: Final answer
   x = 30,192.95