Finding the Third Proportional to 139.50 and 288

Step by Step Solution

1. Step 1: Write the proportion equation
   139.50 : 288 = 288 : x
2. Step 2: Convert to fraction form
   139.50/288 = 288/x
3. Step 3: Cross multiply
   139.50x = 288 × 288
4. Step 4: Simplify right side
   139.50x = 82,944
5. Step 5: Solve for x
   x = 82,944/139.50
6. Step 6: Final answer
   x = 594.58