Finding the Fourth Proportional to 139.83, 209.76 and 123.73

Step by Step Solution

1. Step 1: Write the proportion equation
   139.83 : 209.76 = 123.73 : x
2. Step 2: Convert to fraction form
   139.83/209.76 = 123.73/x
3. Step 3: Cross multiply
   139.83x = 209.76 × 123.73
4. Step 4: Simplify right side
   139.83x = 25,953.60
5. Step 5: Solve for x
   x = 25,953.60/139.83
6. Step 6: Final answer
   x = 185.61