Finding the Fourth Proportional to 139.59, 209.52 and 105.23

Step by Step Solution

1. Step 1: Write the proportion equation
   139.59 : 209.52 = 105.23 : x
2. Step 2: Convert to fraction form
   139.59/209.52 = 105.23/x
3. Step 3: Cross multiply
   139.59x = 209.52 × 105.23
4. Step 4: Simplify right side
   139.59x = 22,048.31
5. Step 5: Solve for x
   x = 22,048.31/139.59
6. Step 6: Final answer
   x = 157.95