Finding the Fourth Proportional to 10,919.34, 16,378.97 and 3,128.15

Step by Step Solution

1. Step 1: Write the proportion equation
   10,919.34 : 16,378.97 = 3,128.15 : x
2. Step 2: Convert to fraction form
   10,919.34/16,378.97 = 3,128.15/x
3. Step 3: Cross multiply
   10,919.34x = 16,378.97 × 3,128.15
4. Step 4: Simplify right side
   10,919.34x = 51,235,900.31
5. Step 5: Solve for x
   x = 51,235,900.31/10,919.34
6. Step 6: Final answer
   x = 4,692.22