Finding the Third Proportional to 111,720 and 217,830

Step by Step Solution

1. Step 1: Write the proportion equation
   111,720 : 217,830 = 217,830 : x
2. Step 2: Convert to fraction form
   111,720/217,830 = 217,830/x
3. Step 3: Cross multiply
   111,720x = 217,830 × 217,830
4. Step 4: Simplify right side
   111,720x = 47,449,908,900
5. Step 5: Solve for x
   x = 47,449,908,900/111,720
6. Step 6: Final answer
   x = 424,721.71