Finding the Fourth Proportional to 28,168.56, 42,263.04 and 13,188.72

Step by Step Solution

1. Step 1: Write the proportion equation
   28,168.56 : 42,263.04 = 13,188.72 : x
2. Step 2: Convert to fraction form
   28,168.56/42,263.04 = 13,188.72/x
3. Step 3: Cross multiply
   28,168.56x = 42,263.04 × 13,188.72
4. Step 4: Simplify right side
   28,168.56x = 557,395,400.91
5. Step 5: Solve for x
   x = 557,395,400.91/28,168.56
6. Step 6: Final answer
   x = 19,787.86