Finding the Third Proportional to 287,407.50 and 435,085.50

Step by Step Solution

1. Step 1: Write the proportion equation
   287,407.50 : 435,085.50 = 435,085.50 : x
2. Step 2: Convert to fraction form
   287,407.50/435,085.50 = 435,085.50/x
3. Step 3: Cross multiply
   287,407.50x = 435,085.50 × 435,085.50
4. Step 4: Simplify right side
   287,407.50x = 189,299,392,310.25
5. Step 5: Solve for x
   x = 189,299,392,310.25/287,407.50
6. Step 6: Final answer
   x = 658,644.58