Finding the Third Proportional to 13,657.78 and 19,678.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,657.78 : 19,678.78 = 19,678.78 : x
2. Step 2: Convert to fraction form
   13,657.78/19,678.78 = 19,678.78/x
3. Step 3: Cross multiply
   13,657.78x = 19,678.78 × 19,678.78
4. Step 4: Simplify right side
   13,657.78x = 387,254,431.49
5. Step 5: Solve for x
   x = 387,254,431.49/13,657.78
6. Step 6: Final answer
   x = 28,354.12