Finding the Third Proportional to 318,144 and 686,101.50

Step by Step Solution

1. Step 1: Write the proportion equation
   318,144 : 686,101.50 = 686,101.50 : x
2. Step 2: Convert to fraction form
   318,144/686,101.50 = 686,101.50/x
3. Step 3: Cross multiply
   318,144x = 686,101.50 × 686,101.50
4. Step 4: Simplify right side
   318,144x = 470,735,268,302.25
5. Step 5: Solve for x
   x = 470,735,268,302.25/318,144
6. Step 6: Final answer
   x = 1,479,629.56