Finding the Fourth Proportional to 28,607.56, 42,876.78 and 12,157

Step by Step Solution

1. Step 1: Write the proportion equation
   28,607.56 : 42,876.78 = 12,157 : x
2. Step 2: Convert to fraction form
   28,607.56/42,876.78 = 12,157/x
3. Step 3: Cross multiply
   28,607.56x = 42,876.78 × 12,157
4. Step 4: Simplify right side
   28,607.56x = 521,253,014.46
5. Step 5: Solve for x
   x = 521,253,014.46/28,607.56
6. Step 6: Final answer
   x = 18,220.81