Finding the Fourth Proportional to 139.82, 209.78 and 67.63

Step by Step Solution

1. Step 1: Write the proportion equation
   139.82 : 209.78 = 67.63 : x
2. Step 2: Convert to fraction form
   139.82/209.78 = 67.63/x
3. Step 3: Cross multiply
   139.82x = 209.78 × 67.63
4. Step 4: Simplify right side
   139.82x = 14,186.56
5. Step 5: Solve for x
   x = 14,186.56/139.82
6. Step 6: Final answer
   x = 101.47