Finding the Fourth Proportional to 21,019.35, 31,498.96 and 9,920.33

Step by Step Solution

1. Step 1: Write the proportion equation
   21,019.35 : 31,498.96 = 9,920.33 : x
2. Step 2: Convert to fraction form
   21,019.35/31,498.96 = 9,920.33/x
3. Step 3: Cross multiply
   21,019.35x = 31,498.96 × 9,920.33
4. Step 4: Simplify right side
   21,019.35x = 312,480,077.86
5. Step 5: Solve for x
   x = 312,480,077.86/21,019.35
6. Step 6: Final answer
   x = 14,866.31