Finding the Third Proportional to 391.50 and 843.56

Step by Step Solution

1. Step 1: Write the proportion equation
   391.50 : 843.56 = 843.56 : x
2. Step 2: Convert to fraction form
   391.50/843.56 = 843.56/x
3. Step 3: Cross multiply
   391.50x = 843.56 × 843.56
4. Step 4: Simplify right side
   391.50x = 711,597.69
5. Step 5: Solve for x
   x = 711,597.69/391.50
6. Step 6: Final answer
   x = 1,817.62