Finding the Third Proportional to 278,577 and 417,870

Step by Step Solution

1. Step 1: Write the proportion equation
   278,577 : 417,870 = 417,870 : x
2. Step 2: Convert to fraction form
   278,577/417,870 = 417,870/x
3. Step 3: Cross multiply
   278,577x = 417,870 × 417,870
4. Step 4: Simplify right side
   278,577x = 174,615,336,900
5. Step 5: Solve for x
   x = 174,615,336,900/278,577
6. Step 6: Final answer
   x = 626,811.75