Finding the Third Proportional to 520.88 and 856.69

Step by Step Solution

1. Step 1: Write the proportion equation
   520.88 : 856.69 = 856.69 : x
2. Step 2: Convert to fraction form
   520.88/856.69 = 856.69/x
3. Step 3: Cross multiply
   520.88x = 856.69 × 856.69
4. Step 4: Simplify right side
   520.88x = 733,913.47
5. Step 5: Solve for x
   x = 733,913.47/520.88
6. Step 6: Final answer
   x = 1,409.00