Finding the Fourth Proportional to 139.69, 209.54 and 105.52

Step by Step Solution

1. Step 1: Write the proportion equation
   139.69 : 209.54 = 105.52 : x
2. Step 2: Convert to fraction form
   139.69/209.54 = 105.52/x
3. Step 3: Cross multiply
   139.69x = 209.54 × 105.52
4. Step 4: Simplify right side
   139.69x = 22,110.20
5. Step 5: Solve for x
   x = 22,110.20/139.69
6. Step 6: Final answer
   x = 158.28