Finding the Fourth Proportional to 20,870.28, 28,800.82 and 11,438.82

Step by Step Solution

1. Step 1: Write the proportion equation
   20,870.28 : 28,800.82 = 11,438.82 : x
2. Step 2: Convert to fraction form
   20,870.28/28,800.82 = 11,438.82/x
3. Step 3: Cross multiply
   20,870.28x = 28,800.82 × 11,438.82
4. Step 4: Simplify right side
   20,870.28x = 329,447,395.83
5. Step 5: Solve for x
   x = 329,447,395.83/20,870.28
6. Step 6: Final answer
   x = 15,785.48