Finding the Fourth Proportional to 22,404.78, 30,919.02 and 12,978.80

Step by Step Solution

1. Step 1: Write the proportion equation
   22,404.78 : 30,919.02 = 12,978.80 : x
2. Step 2: Convert to fraction form
   22,404.78/30,919.02 = 12,978.80/x
3. Step 3: Cross multiply
   22,404.78x = 30,919.02 × 12,978.80
4. Step 4: Simplify right side
   22,404.78x = 401,291,776.78
5. Step 5: Solve for x
   x = 401,291,776.78/22,404.78
6. Step 6: Final answer
   x = 17,910.99