Finding the Fourth Proportional to 21,992.52, 30,342.12 and 12,431.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,992.52 : 30,342.12 = 12,431.28 : x
2. Step 2: Convert to fraction form
   21,992.52/30,342.12 = 12,431.28/x
3. Step 3: Cross multiply
   21,992.52x = 30,342.12 × 12,431.28
4. Step 4: Simplify right side
   21,992.52x = 377,191,389.51
5. Step 5: Solve for x
   x = 377,191,389.51/21,992.52
6. Step 6: Final answer
   x = 17,150.89