Finding the Third Proportional to 373.78 and 400.78

Step by Step Solution

1. Step 1: Write the proportion equation
   373.78 : 400.78 = 400.78 : x
2. Step 2: Convert to fraction form
   373.78/400.78 = 400.78/x
3. Step 3: Cross multiply
   373.78x = 400.78 × 400.78
4. Step 4: Simplify right side
   373.78x = 160,625.61
5. Step 5: Solve for x
   x = 160,625.61/373.78
6. Step 6: Final answer
   x = 429.73