Finding the Fourth Proportional to 139.83, 209.55 and 105.32

Step by Step Solution

1. Step 1: Write the proportion equation
   139.83 : 209.55 = 105.32 : x
2. Step 2: Convert to fraction form
   139.83/209.55 = 105.32/x
3. Step 3: Cross multiply
   139.83x = 209.55 × 105.32
4. Step 4: Simplify right side
   139.83x = 22,068.76
5. Step 5: Solve for x
   x = 22,068.76/139.83
6. Step 6: Final answer
   x = 157.83