Finding the Fourth Proportional to 13,278.79, 19,919.40 and 3,418.10

Step by Step Solution

1. Step 1: Write the proportion equation
   13,278.79 : 19,919.40 = 3,418.10 : x
2. Step 2: Convert to fraction form
   13,278.79/19,919.40 = 3,418.10/x
3. Step 3: Cross multiply
   13,278.79x = 19,919.40 × 3,418.10
4. Step 4: Simplify right side
   13,278.79x = 68,086,384.45
5. Step 5: Solve for x
   x = 68,086,384.45/13,278.79
6. Step 6: Final answer
   x = 5,127.46