Finding the Fourth Proportional to 85,422.10, 128,133.15 and 85,422.10

Step by Step Solution

1. Step 1: Write the proportion equation
   85,422.10 : 128,133.15 = 85,422.10 : x
2. Step 2: Convert to fraction form
   85,422.10/128,133.15 = 85,422.10/x
3. Step 3: Cross multiply
   85,422.10x = 128,133.15 × 85,422.10
4. Step 4: Simplify right side
   85,422.10x = 10,945,402,752.62
5. Step 5: Solve for x
   x = 10,945,402,752.62/85,422.10
6. Step 6: Final answer
   x = 128,133.15