Finding the Fourth Proportional to 21,001.39, 31,501.59 and 8,518.06

Step by Step Solution

1. Step 1: Write the proportion equation
   21,001.39 : 31,501.59 = 8,518.06 : x
2. Step 2: Convert to fraction form
   21,001.39/31,501.59 = 8,518.06/x
3. Step 3: Cross multiply
   21,001.39x = 31,501.59 × 8,518.06
4. Step 4: Simplify right side
   21,001.39x = 268,332,433.72
5. Step 5: Solve for x
   x = 268,332,433.72/21,001.39
6. Step 6: Final answer
   x = 12,776.89