Finding the Fourth Proportional to 139.91, 209.91 and 67.82

Step by Step Solution

1. Step 1: Write the proportion equation
   139.91 : 209.91 = 67.82 : x
2. Step 2: Convert to fraction form
   139.91/209.91 = 67.82/x
3. Step 3: Cross multiply
   139.91x = 209.91 × 67.82
4. Step 4: Simplify right side
   139.91x = 14,236.10
5. Step 5: Solve for x
   x = 14,236.10/139.91
6. Step 6: Final answer
   x = 101.75