Finding the Fourth Proportional to 39,990.88, 55,185.91 and 21,841

Step by Step Solution

1. Step 1: Write the proportion equation
   39,990.88 : 55,185.91 = 21,841 : x
2. Step 2: Convert to fraction form
   39,990.88/55,185.91 = 21,841/x
3. Step 3: Cross multiply
   39,990.88x = 55,185.91 × 21,841
4. Step 4: Simplify right side
   39,990.88x = 1,205,315,460.31
5. Step 5: Solve for x
   x = 1,205,315,460.31/39,990.88
6. Step 6: Final answer
   x = 30,139.76