Finding the Fourth Proportional to 139.78, 209.31 and 116.83

Step by Step Solution

1. Step 1: Write the proportion equation
   139.78 : 209.31 = 116.83 : x
2. Step 2: Convert to fraction form
   139.78/209.31 = 116.83/x
3. Step 3: Cross multiply
   139.78x = 209.31 × 116.83
4. Step 4: Simplify right side
   139.78x = 24,453.69
5. Step 5: Solve for x
   x = 24,453.69/139.78
6. Step 6: Final answer
   x = 174.94