Finding the Fourth Proportional to 21,150.25, 31,721.93 and 7,999.49

Step by Step Solution

1. Step 1: Write the proportion equation
   21,150.25 : 31,721.93 = 7,999.49 : x
2. Step 2: Convert to fraction form
   21,150.25/31,721.93 = 7,999.49/x
3. Step 3: Cross multiply
   21,150.25x = 31,721.93 × 7,999.49
4. Step 4: Simplify right side
   21,150.25x = 253,759,221.82
5. Step 5: Solve for x
   x = 253,759,221.82/21,150.25
6. Step 6: Final answer
   x = 11,997.93