Finding the Third Proportional to 287,056.50 and 422,280

Step by Step Solution

1. Step 1: Write the proportion equation
   287,056.50 : 422,280 = 422,280 : x
2. Step 2: Convert to fraction form
   287,056.50/422,280 = 422,280/x
3. Step 3: Cross multiply
   287,056.50x = 422,280 × 422,280
4. Step 4: Simplify right side
   287,056.50x = 178,320,398,400
5. Step 5: Solve for x
   x = 178,320,398,400/287,056.50
6. Step 6: Final answer
   x = 621,203.14