Finding the Fourth Proportional to 99,978.92, 137,968.56 and 54,657.24

Step by Step Solution

1. Step 1: Write the proportion equation
   99,978.92 : 137,968.56 = 54,657.24 : x
2. Step 2: Convert to fraction form
   99,978.92/137,968.56 = 54,657.24/x
3. Step 3: Cross multiply
   99,978.92x = 137,968.56 × 54,657.24
4. Step 4: Simplify right side
   99,978.92x = 7,540,980,696.37
5. Step 5: Solve for x
   x = 7,540,980,696.37/99,978.92
6. Step 6: Final answer
   x = 75,425.71