Finding the Fourth Proportional to 28,105.56, 42,172.09 and 12,308.42

Step by Step Solution

1. Step 1: Write the proportion equation
   28,105.56 : 42,172.09 = 12,308.42 : x
2. Step 2: Convert to fraction form
   28,105.56/42,172.09 = 12,308.42/x
3. Step 3: Cross multiply
   28,105.56x = 42,172.09 × 12,308.42
4. Step 4: Simplify right side
   28,105.56x = 519,071,870.66
5. Step 5: Solve for x
   x = 519,071,870.66/28,105.56
6. Step 6: Final answer
   x = 18,468.65