Finding the Fourth Proportional to 139.69, 209.54 and 43.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139.69 : 209.54 = 43.50 : x
2. Step 2: Convert to fraction form
   139.69/209.54 = 43.50/x
3. Step 3: Cross multiply
   139.69x = 209.54 × 43.50
4. Step 4: Simplify right side
   139.69x = 9,115.10
5. Step 5: Solve for x
   x = 9,115.10/139.69
6. Step 6: Final answer
   x = 65.25