Finding the Fourth Proportional to 139,431, 209,060.64 and 83,260.20

Step by Step Solution

1. Step 1: Write the proportion equation
   139,431 : 209,060.64 = 83,260.20 : x
2. Step 2: Convert to fraction form
   139,431/209,060.64 = 83,260.20/x
3. Step 3: Cross multiply
   139,431x = 209,060.64 × 83,260.20
4. Step 4: Simplify right side
   139,431x = 17,406,430,698.53
5. Step 5: Solve for x
   x = 17,406,430,698.53/139,431
6. Step 6: Final answer
   x = 124,839.03