Finding the Fourth Proportional to 12,821.96, 17,680.02 and 10,515.38

Step by Step Solution

1. Step 1: Write the proportion equation
   12,821.96 : 17,680.02 = 10,515.38 : x
2. Step 2: Convert to fraction form
   12,821.96/17,680.02 = 10,515.38/x
3. Step 3: Cross multiply
   12,821.96x = 17,680.02 × 10,515.38
4. Step 4: Simplify right side
   12,821.96x = 185,912,128.71
5. Step 5: Solve for x
   x = 185,912,128.71/12,821.96
6. Step 6: Final answer
   x = 14,499.51