Finding the Fourth Proportional to 39,072.88, 53,920.59 and 21,168.01

Step by Step Solution

1. Step 1: Write the proportion equation
   39,072.88 : 53,920.59 = 21,168.01 : x
2. Step 2: Convert to fraction form
   39,072.88/53,920.59 = 21,168.01/x
3. Step 3: Cross multiply
   39,072.88x = 53,920.59 × 21,168.01
4. Step 4: Simplify right side
   39,072.88x = 1,141,391,318.72
5. Step 5: Solve for x
   x = 1,141,391,318.72/39,072.88
6. Step 6: Final answer
   x = 29,211.86