Finding the Fourth Proportional to 99,456.54, 137,256.57 and 57,015.78

Step by Step Solution

1. Step 1: Write the proportion equation
   99,456.54 : 137,256.57 = 57,015.78 : x
2. Step 2: Convert to fraction form
   99,456.54/137,256.57 = 57,015.78/x
3. Step 3: Cross multiply
   99,456.54x = 137,256.57 × 57,015.78
4. Step 4: Simplify right side
   99,456.54x = 7,825,790,398.67
5. Step 5: Solve for x
   x = 7,825,790,398.67/99,456.54
6. Step 6: Final answer
   x = 78,685.53