Finding the Fourth Proportional to 22,405.38, 30,916 and 12,972.12

Step by Step Solution

1. Step 1: Write the proportion equation
   22,405.38 : 30,916 = 12,972.12 : x
2. Step 2: Convert to fraction form
   22,405.38/30,916 = 12,972.12/x
3. Step 3: Cross multiply
   22,405.38x = 30,916 × 12,972.12
4. Step 4: Simplify right side
   22,405.38x = 401,046,061.92
5. Step 5: Solve for x
   x = 401,046,061.92/22,405.38
6. Step 6: Final answer
   x = 17,899.54