Finding the Fourth Proportional to 82,421.30, 123,891.15 and 80,866.10

Step by Step Solution

1. Step 1: Write the proportion equation
   82,421.30 : 123,891.15 = 80,866.10 : x
2. Step 2: Convert to fraction form
   82,421.30/123,891.15 = 80,866.10/x
3. Step 3: Cross multiply
   82,421.30x = 123,891.15 × 80,866.10
4. Step 4: Simplify right side
   82,421.30x = 10,018,594,125.02
5. Step 5: Solve for x
   x = 10,018,594,125.02/82,421.30
6. Step 6: Final answer
   x = 121,553.46