Finding the Third Proportional to 287,806 and 435,724

Step by Step Solution

1. Step 1: Write the proportion equation
   287,806 : 435,724 = 435,724 : x
2. Step 2: Convert to fraction form
   287,806/435,724 = 435,724/x
3. Step 3: Cross multiply
   287,806x = 435,724 × 435,724
4. Step 4: Simplify right side
   287,806x = 189,855,404,176
5. Step 5: Solve for x
   x = 189,855,404,176/287,806
6. Step 6: Final answer
   x = 659,664.51