Finding the Fourth Proportional to 21,936.72, 30,263.40 and 13,442.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,936.72 : 30,263.40 = 13,442.16 : x
2. Step 2: Convert to fraction form
   21,936.72/30,263.40 = 13,442.16/x
3. Step 3: Cross multiply
   21,936.72x = 30,263.40 × 13,442.16
4. Step 4: Simplify right side
   21,936.72x = 406,805,464.94
5. Step 5: Solve for x
   x = 406,805,464.94/21,936.72
6. Step 6: Final answer
   x = 18,544.50