Finding the Fourth Proportional to 15,801.55, 21,806.15 and 8,631.56

Step by Step Solution

1. Step 1: Write the proportion equation
   15,801.55 : 21,806.15 = 8,631.56 : x
2. Step 2: Convert to fraction form
   15,801.55/21,806.15 = 8,631.56/x
3. Step 3: Cross multiply
   15,801.55x = 21,806.15 × 8,631.56
4. Step 4: Simplify right side
   15,801.55x = 188,221,103.45
5. Step 5: Solve for x
   x = 188,221,103.45/15,801.55
6. Step 6: Final answer
   x = 11,911.56