Finding the Third Proportional to 288,396 and 621,166.50

Step by Step Solution

1. Step 1: Write the proportion equation
   288,396 : 621,166.50 = 621,166.50 : x
2. Step 2: Convert to fraction form
   288,396/621,166.50 = 621,166.50/x
3. Step 3: Cross multiply
   288,396x = 621,166.50 × 621,166.50
4. Step 4: Simplify right side
   288,396x = 385,847,820,722.25
5. Step 5: Solve for x
   x = 385,847,820,722.25/288,396
6. Step 6: Final answer
   x = 1,337,909.75