Finding the Third Proportional to 213,116.50 and 318,216

Step by Step Solution

1. Step 1: Write the proportion equation
   213,116.50 : 318,216 = 318,216 : x
2. Step 2: Convert to fraction form
   213,116.50/318,216 = 318,216/x
3. Step 3: Cross multiply
   213,116.50x = 318,216 × 318,216
4. Step 4: Simplify right side
   213,116.50x = 101,261,422,656
5. Step 5: Solve for x
   x = 101,261,422,656/213,116.50
6. Step 6: Final answer
   x = 475,145.86