Finding the Fourth Proportional to 23,142, 31,940.28 and 13,206

Step by Step Solution

1. Step 1: Write the proportion equation
   23,142 : 31,940.28 = 13,206 : x
2. Step 2: Convert to fraction form
   23,142/31,940.28 = 13,206/x
3. Step 3: Cross multiply
   23,142x = 31,940.28 × 13,206
4. Step 4: Simplify right side
   23,142x = 421,803,337.68
5. Step 5: Solve for x
   x = 421,803,337.68/23,142
6. Step 6: Final answer
   x = 18,226.75