Finding the Fourth Proportional to 85,815.30, 128,759.40 and 41,419.20

Step by Step Solution

1. Step 1: Write the proportion equation
   85,815.30 : 128,759.40 = 41,419.20 : x
2. Step 2: Convert to fraction form
   85,815.30/128,759.40 = 41,419.20/x
3. Step 3: Cross multiply
   85,815.30x = 128,759.40 × 41,419.20
4. Step 4: Simplify right side
   85,815.30x = 5,333,111,340.48
5. Step 5: Solve for x
   x = 5,333,111,340.48/85,815.30
6. Step 6: Final answer
   x = 62,146.39