Finding the Fourth Proportional to 28,300.24, 42,435.78 and 12,704.50

Step by Step Solution

1. Step 1: Write the proportion equation
   28,300.24 : 42,435.78 = 12,704.50 : x
2. Step 2: Convert to fraction form
   28,300.24/42,435.78 = 12,704.50/x
3. Step 3: Cross multiply
   28,300.24x = 42,435.78 × 12,704.50
4. Step 4: Simplify right side
   28,300.24x = 539,125,367.01
5. Step 5: Solve for x
   x = 539,125,367.01/28,300.24
6. Step 6: Final answer
   x = 19,050.20