Finding the Third Proportional to 661.78 and 981.42

Step by Step Solution

1. Step 1: Write the proportion equation
   661.78 : 981.42 = 981.42 : x
2. Step 2: Convert to fraction form
   661.78/981.42 = 981.42/x
3. Step 3: Cross multiply
   661.78x = 981.42 × 981.42
4. Step 4: Simplify right side
   661.78x = 963,188.90
5. Step 5: Solve for x
   x = 963,188.90/661.78
6. Step 6: Final answer
   x = 1,455.45