Finding the Third Proportional to 207,642 and 318,316.50

Step by Step Solution

1. Step 1: Write the proportion equation
   207,642 : 318,316.50 = 318,316.50 : x
2. Step 2: Convert to fraction form
   207,642/318,316.50 = 318,316.50/x
3. Step 3: Cross multiply
   207,642x = 318,316.50 × 318,316.50
4. Step 4: Simplify right side
   207,642x = 101,325,394,172.25
5. Step 5: Solve for x
   x = 101,325,394,172.25/207,642
6. Step 6: Final answer
   x = 487,981.21