Finding the Fourth Proportional to 28,142.49, 42,228.27 and 12,358.60

Step by Step Solution

1. Step 1: Write the proportion equation
   28,142.49 : 42,228.27 = 12,358.60 : x
2. Step 2: Convert to fraction form
   28,142.49/42,228.27 = 12,358.60/x
3. Step 3: Cross multiply
   28,142.49x = 42,228.27 × 12,358.60
4. Step 4: Simplify right side
   28,142.49x = 521,882,362.96
5. Step 5: Solve for x
   x = 521,882,362.96/28,142.49
6. Step 6: Final answer
   x = 18,544.28