Finding the Third Proportional to 521.86 and 807.89

Step by Step Solution

1. Step 1: Write the proportion equation
   521.86 : 807.89 = 807.89 : x
2. Step 2: Convert to fraction form
   521.86/807.89 = 807.89/x
3. Step 3: Cross multiply
   521.86x = 807.89 × 807.89
4. Step 4: Simplify right side
   521.86x = 652,687.26
5. Step 5: Solve for x
   x = 652,687.26/521.86
6. Step 6: Final answer
   x = 1,250.70