Finding the Fourth Proportional to 11,945.29, 17,921 and 8,442.25

Step by Step Solution

1. Step 1: Write the proportion equation
   11,945.29 : 17,921 = 8,442.25 : x
2. Step 2: Convert to fraction form
   11,945.29/17,921 = 8,442.25/x
3. Step 3: Cross multiply
   11,945.29x = 17,921 × 8,442.25
4. Step 4: Simplify right side
   11,945.29x = 151,293,562.25
5. Step 5: Solve for x
   x = 151,293,562.25/11,945.29
6. Step 6: Final answer
   x = 12,665.54