Finding the Third Proportional to 291,217.50 and 636,315

Step by Step Solution

1. Step 1: Write the proportion equation
   291,217.50 : 636,315 = 636,315 : x
2. Step 2: Convert to fraction form
   291,217.50/636,315 = 636,315/x
3. Step 3: Cross multiply
   291,217.50x = 636,315 × 636,315
4. Step 4: Simplify right side
   291,217.50x = 404,896,779,225
5. Step 5: Solve for x
   x = 404,896,779,225/291,217.50
6. Step 6: Final answer
   x = 1,390,358.68