Finding the Fourth Proportional to 3,404.31, 5,106.45 and 939.15

Step by Step Solution

1. Step 1: Write the proportion equation
   3,404.31 : 5,106.45 = 939.15 : x
2. Step 2: Convert to fraction form
   3,404.31/5,106.45 = 939.15/x
3. Step 3: Cross multiply
   3,404.31x = 5,106.45 × 939.15
4. Step 4: Simplify right side
   3,404.31x = 4,795,722.52
5. Step 5: Solve for x
   x = 4,795,722.52/3,404.31
6. Step 6: Final answer
   x = 1,408.72