Finding the Third Proportional to 291,142.69 and 636,261.75

Step by Step Solution

1. Step 1: Write the proportion equation
   291,142.69 : 636,261.75 = 636,261.75 : x
2. Step 2: Convert to fraction form
   291,142.69/636,261.75 = 636,261.75/x
3. Step 3: Cross multiply
   291,142.69x = 636,261.75 × 636,261.75
4. Step 4: Simplify right side
   291,142.69x = 404,829,014,513.06
5. Step 5: Solve for x
   x = 404,829,014,513.06/291,142.69
6. Step 6: Final answer
   x = 1,390,483.20