Finding the Fourth Proportional to 28,167.20, 42,262.88 and 13,386.56

Step by Step Solution

1. Step 1: Write the proportion equation
   28,167.20 : 42,262.88 = 13,386.56 : x
2. Step 2: Convert to fraction form
   28,167.20/42,262.88 = 13,386.56/x
3. Step 3: Cross multiply
   28,167.20x = 42,262.88 × 13,386.56
4. Step 4: Simplify right side
   28,167.20x = 565,754,578.89
5. Step 5: Solve for x
   x = 565,754,578.89/28,167.20
6. Step 6: Final answer
   x = 20,085.58