Finding the Third Proportional to 423,806.50 and 640,030

Step by Step Solution

1. Step 1: Write the proportion equation
   423,806.50 : 640,030 = 640,030 : x
2. Step 2: Convert to fraction form
   423,806.50/640,030 = 640,030/x
3. Step 3: Cross multiply
   423,806.50x = 640,030 × 640,030
4. Step 4: Simplify right side
   423,806.50x = 409,638,400,900
5. Step 5: Solve for x
   x = 409,638,400,900/423,806.50
6. Step 6: Final answer
   x = 966,569.42