Finding the Fourth Proportional to 139.52, 209.17 and 109.15

Step by Step Solution

1. Step 1: Write the proportion equation
   139.52 : 209.17 = 109.15 : x
2. Step 2: Convert to fraction form
   139.52/209.17 = 109.15/x
3. Step 3: Cross multiply
   139.52x = 209.17 × 109.15
4. Step 4: Simplify right side
   139.52x = 22,830.91
5. Step 5: Solve for x
   x = 22,830.91/139.52
6. Step 6: Final answer
   x = 163.64