Finding the Fourth Proportional to 21,759.86, 30,031.02 and 12,809.57

Step by Step Solution

1. Step 1: Write the proportion equation
   21,759.86 : 30,031.02 = 12,809.57 : x
2. Step 2: Convert to fraction form
   21,759.86/30,031.02 = 12,809.57/x
3. Step 3: Cross multiply
   21,759.86x = 30,031.02 × 12,809.57
4. Step 4: Simplify right side
   21,759.86x = 384,684,452.86
5. Step 5: Solve for x
   x = 384,684,452.86/21,759.86
6. Step 6: Final answer
   x = 17,678.63