Finding the Third Proportional to 212,838 and 318,670.50

Step by Step Solution

1. Step 1: Write the proportion equation
   212,838 : 318,670.50 = 318,670.50 : x
2. Step 2: Convert to fraction form
   212,838/318,670.50 = 318,670.50/x
3. Step 3: Cross multiply
   212,838x = 318,670.50 × 318,670.50
4. Step 4: Simplify right side
   212,838x = 101,550,887,570.25
5. Step 5: Solve for x
   x = 101,550,887,570.25/212,838
6. Step 6: Final answer
   x = 477,127.62