Finding the Fourth Proportional to 139.86, 209.82 and 48.56

Step by Step Solution

1. Step 1: Write the proportion equation
   139.86 : 209.82 = 48.56 : x
2. Step 2: Convert to fraction form
   139.86/209.82 = 48.56/x
3. Step 3: Cross multiply
   139.86x = 209.82 × 48.56
4. Step 4: Simplify right side
   139.86x = 10,188.86
5. Step 5: Solve for x
   x = 10,188.86/139.86
6. Step 6: Final answer
   x = 72.85