Finding the Fourth Proportional to 21,100.51, 31,622.82 and 11,218.51

Step by Step Solution

1. Step 1: Write the proportion equation
   21,100.51 : 31,622.82 = 11,218.51 : x
2. Step 2: Convert to fraction form
   21,100.51/31,622.82 = 11,218.51/x
3. Step 3: Cross multiply
   21,100.51x = 31,622.82 × 11,218.51
4. Step 4: Simplify right side
   21,100.51x = 354,760,922.40
5. Step 5: Solve for x
   x = 354,760,922.40/21,100.51
6. Step 6: Final answer
   x = 16,812.91