Finding the Fourth Proportional to 39,021.72, 53,849.55 and 21,116.34

Step by Step Solution

1. Step 1: Write the proportion equation
   39,021.72 : 53,849.55 = 21,116.34 : x
2. Step 2: Convert to fraction form
   39,021.72/53,849.55 = 21,116.34/x
3. Step 3: Cross multiply
   39,021.72x = 53,849.55 × 21,116.34
4. Step 4: Simplify right side
   39,021.72x = 1,137,105,406.65
5. Step 5: Solve for x
   x = 1,137,105,406.65/39,021.72
6. Step 6: Final answer
   x = 29,140.32