Finding the Third Proportional to 218,978 and 470,690

Step by Step Solution

1. Step 1: Write the proportion equation
   218,978 : 470,690 = 470,690 : x
2. Step 2: Convert to fraction form
   218,978/470,690 = 470,690/x
3. Step 3: Cross multiply
   218,978x = 470,690 × 470,690
4. Step 4: Simplify right side
   218,978x = 221,549,076,100
5. Step 5: Solve for x
   x = 221,549,076,100/218,978
6. Step 6: Final answer
   x = 1,011,741.25