Finding the Fourth Proportional to 120,393.89, 166,144.80 and 72,638.02

Step by Step Solution

1. Step 1: Write the proportion equation
   120,393.89 : 166,144.80 = 72,638.02 : x
2. Step 2: Convert to fraction form
   120,393.89/166,144.80 = 72,638.02/x
3. Step 3: Cross multiply
   120,393.89x = 166,144.80 × 72,638.02
4. Step 4: Simplify right side
   120,393.89x = 12,068,428,237.92
5. Step 5: Solve for x
   x = 12,068,428,237.92/120,393.89
6. Step 6: Final answer
   x = 100,241.20