Finding the Fourth Proportional to 21,298.30, 31,951.29 and 7,257.55

Step by Step Solution

1. Step 1: Write the proportion equation
   21,298.30 : 31,951.29 = 7,257.55 : x
2. Step 2: Convert to fraction form
   21,298.30/31,951.29 = 7,257.55/x
3. Step 3: Cross multiply
   21,298.30x = 31,951.29 × 7,257.55
4. Step 4: Simplify right side
   21,298.30x = 231,888,084.74
5. Step 5: Solve for x
   x = 231,888,084.74/21,298.30
6. Step 6: Final answer
   x = 10,887.63