Finding the Fourth Proportional to 21,016.89, 31,519.18 and 7,866.18

Step by Step Solution

1. Step 1: Write the proportion equation
   21,016.89 : 31,519.18 = 7,866.18 : x
2. Step 2: Convert to fraction form
   21,016.89/31,519.18 = 7,866.18/x
3. Step 3: Cross multiply
   21,016.89x = 31,519.18 × 7,866.18
4. Step 4: Simplify right side
   21,016.89x = 247,935,543.33
5. Step 5: Solve for x
   x = 247,935,543.33/21,016.89
6. Step 6: Final answer
   x = 11,796.97