Finding the Fourth Proportional to 139.76, 209.50 and 48.42

Step by Step Solution

1. Step 1: Write the proportion equation
   139.76 : 209.50 = 48.42 : x
2. Step 2: Convert to fraction form
   139.76/209.50 = 48.42/x
3. Step 3: Cross multiply
   139.76x = 209.50 × 48.42
4. Step 4: Simplify right side
   139.76x = 10,143.99
5. Step 5: Solve for x
   x = 10,143.99/139.76
6. Step 6: Final answer
   x = 72.58