Finding the Third Proportional to 711.56 and 839.81

Step by Step Solution

1. Step 1: Write the proportion equation
   711.56 : 839.81 = 839.81 : x
2. Step 2: Convert to fraction form
   711.56/839.81 = 839.81/x
3. Step 3: Cross multiply
   711.56x = 839.81 × 839.81
4. Step 4: Simplify right side
   711.56x = 705,285.04
5. Step 5: Solve for x
   x = 705,285.04/711.56
6. Step 6: Final answer
   x = 991.18