Finding the Third Proportional to 257,388 and 404,178

Step by Step Solution

1. Step 1: Write the proportion equation
   257,388 : 404,178 = 404,178 : x
2. Step 2: Convert to fraction form
   257,388/404,178 = 404,178/x
3. Step 3: Cross multiply
   257,388x = 404,178 × 404,178
4. Step 4: Simplify right side
   257,388x = 163,359,855,684
5. Step 5: Solve for x
   x = 163,359,855,684/257,388
6. Step 6: Final answer
   x = 634,683.26