Finding the Third Proportional to 291,140 and 636,412

Step by Step Solution

1. Step 1: Write the proportion equation
   291,140 : 636,412 = 636,412 : x
2. Step 2: Convert to fraction form
   291,140/636,412 = 636,412/x
3. Step 3: Cross multiply
   291,140x = 636,412 × 636,412
4. Step 4: Simplify right side
   291,140x = 405,020,233,744
5. Step 5: Solve for x
   x = 405,020,233,744/291,140
6. Step 6: Final answer
   x = 1,391,152.83