Finding the Fourth Proportional to 139.83, 209.67 and 71.33

Step by Step Solution

1. Step 1: Write the proportion equation
   139.83 : 209.67 = 71.33 : x
2. Step 2: Convert to fraction form
   139.83/209.67 = 71.33/x
3. Step 3: Cross multiply
   139.83x = 209.67 × 71.33
4. Step 4: Simplify right side
   139.83x = 14,954.71
5. Step 5: Solve for x
   x = 14,954.71/139.83
6. Step 6: Final answer
   x = 106.95