Finding the Third Proportional to 139.61 and 328.61

Step by Step Solution

1. Step 1: Write the proportion equation
   139.61 : 328.61 = 328.61 : x
2. Step 2: Convert to fraction form
   139.61/328.61 = 328.61/x
3. Step 3: Cross multiply
   139.61x = 328.61 × 328.61
4. Step 4: Simplify right side
   139.61x = 107,981.55
5. Step 5: Solve for x
   x = 107,981.55/139.61
6. Step 6: Final answer
   x = 773.48