Finding the Fourth Proportional to 139.86, 209.76 and 43.69

Step by Step Solution

1. Step 1: Write the proportion equation
   139.86 : 209.76 = 43.69 : x
2. Step 2: Convert to fraction form
   139.86/209.76 = 43.69/x
3. Step 3: Cross multiply
   139.86x = 209.76 × 43.69
4. Step 4: Simplify right side
   139.86x = 9,164.41
5. Step 5: Solve for x
   x = 9,164.41/139.86
6. Step 6: Final answer
   x = 65.53