Finding the Third Proportional to 287,253 and 386,410.50

Step by Step Solution

1. Step 1: Write the proportion equation
   287,253 : 386,410.50 = 386,410.50 : x
2. Step 2: Convert to fraction form
   287,253/386,410.50 = 386,410.50/x
3. Step 3: Cross multiply
   287,253x = 386,410.50 × 386,410.50
4. Step 4: Simplify right side
   287,253x = 149,313,074,510.25
5. Step 5: Solve for x
   x = 149,313,074,510.25/287,253
6. Step 6: Final answer
   x = 519,796.40