Finding the Third Proportional to 386,205 and 807,697.50

Step by Step Solution

1. Step 1: Write the proportion equation
   386,205 : 807,697.50 = 807,697.50 : x
2. Step 2: Convert to fraction form
   386,205/807,697.50 = 807,697.50/x
3. Step 3: Cross multiply
   386,205x = 807,697.50 × 807,697.50
4. Step 4: Simplify right side
   386,205x = 652,375,251,506.25
5. Step 5: Solve for x
   x = 652,375,251,506.25/386,205
6. Step 6: Final answer
   x = 1,689,194.21