Finding the Fourth Proportional to 21,008.72, 31,279.84 and 20,714.51

Step by Step Solution

1. Step 1: Write the proportion equation
   21,008.72 : 31,279.84 = 20,714.51 : x
2. Step 2: Convert to fraction form
   21,008.72/31,279.84 = 20,714.51/x
3. Step 3: Cross multiply
   21,008.72x = 31,279.84 × 20,714.51
4. Step 4: Simplify right side
   21,008.72x = 647,946,584.89
5. Step 5: Solve for x
   x = 647,946,584.89/21,008.72
6. Step 6: Final answer
   x = 30,841.79