Finding the Fourth Proportional to 139,928.36, 209,760.30 and 55,740.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,928.36 : 209,760.30 = 55,740.50 : x
2. Step 2: Convert to fraction form
   139,928.36/209,760.30 = 55,740.50/x
3. Step 3: Cross multiply
   139,928.36x = 209,760.30 × 55,740.50
4. Step 4: Simplify right side
   139,928.36x = 11,692,144,002.15
5. Step 5: Solve for x
   x = 11,692,144,002.15/139,928.36
6. Step 6: Final answer
   x = 83,558.07