Finding the Fourth Proportional to 12,838.39, 17,715.20 and 7,172.42

Step by Step Solution

1. Step 1: Write the proportion equation
   12,838.39 : 17,715.20 = 7,172.42 : x
2. Step 2: Convert to fraction form
   12,838.39/17,715.20 = 7,172.42/x
3. Step 3: Cross multiply
   12,838.39x = 17,715.20 × 7,172.42
4. Step 4: Simplify right side
   12,838.39x = 127,060,917.00
5. Step 5: Solve for x
   x = 127,060,917.00/12,838.39
6. Step 6: Final answer
   x = 9,896.95