Finding the Fourth Proportional to 90,648.88, 124,651.80 and 78,691.30

Step by Step Solution

1. Step 1: Write the proportion equation
   90,648.88 : 124,651.80 = 78,691.30 : x
2. Step 2: Convert to fraction form
   90,648.88/124,651.80 = 78,691.30/x
3. Step 3: Cross multiply
   90,648.88x = 124,651.80 × 78,691.30
4. Step 4: Simplify right side
   90,648.88x = 9,809,012,189.34
5. Step 5: Solve for x
   x = 9,809,012,189.34/90,648.88
6. Step 6: Final answer
   x = 108,208.86