Finding the Third Proportional to 278,556 and 430,612.50

Step by Step Solution

1. Step 1: Write the proportion equation
   278,556 : 430,612.50 = 430,612.50 : x
2. Step 2: Convert to fraction form
   278,556/430,612.50 = 430,612.50/x
3. Step 3: Cross multiply
   278,556x = 430,612.50 × 430,612.50
4. Step 4: Simplify right side
   278,556x = 185,427,125,156.25
5. Step 5: Solve for x
   x = 185,427,125,156.25/278,556
6. Step 6: Final answer
   x = 665,672.70