Finding the Fourth Proportional to 28,553.16, 42,839.82 and 12,756.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28,553.16 : 42,839.82 = 12,756.72 : x
2. Step 2: Convert to fraction form
   28,553.16/42,839.82 = 12,756.72/x
3. Step 3: Cross multiply
   28,553.16x = 42,839.82 × 12,756.72
4. Step 4: Simplify right side
   28,553.16x = 546,495,588.59
5. Step 5: Solve for x
   x = 546,495,588.59/28,553.16
6. Step 6: Final answer
   x = 19,139.58