Finding the Fourth Proportional to 13,278.69, 19,918.58 and 3,918.71

Step by Step Solution

1. Step 1: Write the proportion equation
   13,278.69 : 19,918.58 = 3,918.71 : x
2. Step 2: Convert to fraction form
   13,278.69/19,918.58 = 3,918.71/x
3. Step 3: Cross multiply
   13,278.69x = 19,918.58 × 3,918.71
4. Step 4: Simplify right side
   13,278.69x = 78,055,039.04
5. Step 5: Solve for x
   x = 78,055,039.04/13,278.69
6. Step 6: Final answer
   x = 5,878.22