Finding the Fourth Proportional to 139.34, 209.00 and 43.15

Step by Step Solution

1. Step 1: Write the proportion equation
   139.34 : 209.00 = 43.15 : x
2. Step 2: Convert to fraction form
   139.34/209.00 = 43.15/x
3. Step 3: Cross multiply
   139.34x = 209.00 × 43.15
4. Step 4: Simplify right side
   139.34x = 9,017.94
5. Step 5: Solve for x
   x = 9,017.94/139.34
6. Step 6: Final answer
   x = 64.72