Finding the Third Proportional to 290,387 and 435,580.50

Step by Step Solution

1. Step 1: Write the proportion equation
   290,387 : 435,580.50 = 435,580.50 : x
2. Step 2: Convert to fraction form
   290,387/435,580.50 = 435,580.50/x
3. Step 3: Cross multiply
   290,387x = 435,580.50 × 435,580.50
4. Step 4: Simplify right side
   290,387x = 189,730,371,980.25
5. Step 5: Solve for x
   x = 189,730,371,980.25/290,387
6. Step 6: Final answer
   x = 653,370.75