Finding the Third Proportional to 711 and 1,039.50

Step by Step Solution

1. Step 1: Write the proportion equation
   711 : 1,039.50 = 1,039.50 : x
2. Step 2: Convert to fraction form
   711/1,039.50 = 1,039.50/x
3. Step 3: Cross multiply
   711x = 1,039.50 × 1,039.50
4. Step 4: Simplify right side
   711x = 1,080,560.25
5. Step 5: Solve for x
   x = 1,080,560.25/711
6. Step 6: Final answer
   x = 1,519.78