Finding the Fourth Proportional to 28,142.72, 42,190.72 and 10,602.88

Step by Step Solution

1. Step 1: Write the proportion equation
   28,142.72 : 42,190.72 = 10,602.88 : x
2. Step 2: Convert to fraction form
   28,142.72/42,190.72 = 10,602.88/x
3. Step 3: Cross multiply
   28,142.72x = 42,190.72 × 10,602.88
4. Step 4: Simplify right side
   28,142.72x = 447,343,141.27
5. Step 5: Solve for x
   x = 447,343,141.27/28,142.72
6. Step 6: Final answer
   x = 15,895.52