Finding the Third Proportional to 255,388 and 404,196

Step by Step Solution

1. Step 1: Write the proportion equation
   255,388 : 404,196 = 404,196 : x
2. Step 2: Convert to fraction form
   255,388/404,196 = 404,196/x
3. Step 3: Cross multiply
   255,388x = 404,196 × 404,196
4. Step 4: Simplify right side
   255,388x = 163,374,406,416
5. Step 5: Solve for x
   x = 163,374,406,416/255,388
6. Step 6: Final answer
   x = 639,710.58